WO2026006147A1 - Gpc3 binding domain comprising chimeric antigen receptors - Google Patents

Abstract

Provided are GPC3 binding CAR polypeptides, nucleic acids (e.g., mRNA) encoding same, and delivery vehicles (e.g., LNPs) formulated with the nucleic acids. These GPC3 binding CARs can be used to treat any disease with abnormal GPC3 expression, e.g., GPC3+ cancers or tumors, in a subject (e.g., human) in need thereof.

Description

Attorney Docket No.: 45817-0177WO1 / MTX980.20 GPC3 BINDING DOMAIN COMPRISING CHIMERIC ANTIGEN RECEPTORS CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of priority of U.S. Provisional Appl. No. 5 63/663,890 filed June 25, 2024, and U.S. Provisional Appl. No.63/715,977 filed November 4, 2024, the contents of both of which are incorporated by reference herein in their entirety. SEQUENCE LISTING 10 The instant application contains a Sequence Listing which has been submitted electronically in XML format and is hereby incorporated by reference in its entirety. Said XML copy, created on June 17, 2025, is named 45817-0177WO1_SL.xml and is 1,450,616 bytes in size. BACKGROUND 15 Glypican 3 (GPC3) is an oncofetal cell-surface glycoprotein comprising heparan sulfate glycosaminoglycan chains and an inner protein core. It has important functions in cellular signaling, modulating regulation of cellular functions such as cell growth, embryogenesis, and differentiation. GPC3 has been associated with a variety of diseases, disorders, and/or conditions, including, for example, cancer. GPC3 is thus an important 20 therapeutic target. Accordingly, there remains a need for therapeutic agents such as antibodies, binding domains, and related proteins (e.g., chimeric antigen receptors or “CARs”, bispecific antibodies, etc.) that bind GPC3 and nucleic acids encoding the same. SUMMARY This disclosure features human GPC3-binding CAR polypeptides and nucleic 25 acids (e.g., mRNA) encoding same. The inventors have surprisingly found that using the delivery vehicles described herein mRNA encoding the human GPC3 binding CAR of this disclosure can be administered in vivo to the subject that allows sufficient expression in macrophages. In other words, the delivery vehicles in which the mRNA encoding the 1 Attorney Docket No.: 45817-0177WO1 / MTX980.20 human GPC3 binding CAR is formulated permit administration of the mRNA to the subject without needing to rely on administering to the subject macrophages that have been transformed with the mRNA ex vivo. In some cases, the delivery vehicle is a lipid nanoparticle and comprises an ionizable lipid, a structural lipid, a phospholipid, and a 5 polyethylene glycol (PEG)-modified lipid. In some cases, the delivery vehicle is a lipid nanoparticle (referred to herein as “LNP2”) and comprises heptadecan-9-yl 8-((2- hydroxyethyl)(8-(nonyloxy)-8-oxooctyl)amino)octanoate (Compound II), 134-hydroxy- 3,6,9,12,15,18,21,24,27,30,33,36,39,42,45,48,51,54,57,60,63,66,69,72,75,78,81,84,87,90, 93,96,99,102,105,108,111,114,117,120,123,126,129,132-10 tetratetracontaoxatetratriacontahectyl stearate (Compound I), 1,2-distearoyl-sn-glycero-3- phosphocholine (DSPC) (Compound IV) , and Cholesterol. In certain cases, the delivery vehicle is a lipid nanoparticle (referred to herein as “LNP1”) and comprises heptadecan- 9-yl 8-((2-hydroxyethyl)(8-(nonyloxy)-8-oxooctyl)amino)octanoate (Compound II), PEG-DMG, 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) (Compound IV), and15 Cholesterol. In other cases, the delivery vehicle comprises 3-butylheptyl 8-((8- (heptadecan-9-yloxy)-8-oxooctyl)(2-hydroxyethyl)amino)octanoate (Compound III), 134-hydroxy- 3,6,9,12,15,18,21,24,27,30,33,36,39,42,45,48,51,54,57,60,63,66,69,72,75,78,81,84,87,90, 93,96,99,102,105,108,111,114,117,120,123,126,129,132- 20 tetratetracontaoxatetratriacontahectyl stearate (Compound I), DMPS (Compound V), and Cholesterol. In other cases, the delivery vehicle is a LNP referred to as “LNP9” and comprises Compound III, Compound IV, Cholesterol, Compound I, and Compound V. In certain cases, the LNP comprises Compound II, Compound IV, Compound I, and Cholesterol (e.g., about 48 mol% Compound II, about 11 mol% Compound IV, about 39 25 mol% cholesterol, and about 2 mol% Compound I). In other cases, the LNP comprises Compound II, Compound IV, PEG-DMG, and Cholesterol (e.g., about 48 mol% Compound II, about 11 mol% Compound IV, about 39.5 mol% cholesterol, and about 1.5 mol% PEG-DMG). In some cases, the LNP comprises Compound III, Compound IV, Cholesterol, Compound I, and Compound V (e.g., about 39.70 mol% Compound III, 2 Attorney Docket No.: 45817-0177WO1 / MTX980.20 about 18.70 mol % Compound IV, about 34.50 mol % Cholesterol, about 3.00 mol % Compound I, and about 4.10 mol % Compound V). In one aspect, this disclosure features a chimeric antigen receptor (CAR) comprising an anti-human GPC3 VHH comprising a VHH-CDR1, a VHH-CDR2, and a 5 VHH-CDR3 of SEQ ID NO:2, 150, or 151. The CAR further comprises a CD28 hinge region linked at its C-terminus to the N-terminus of a CD28 transmembrane domain. The C-terminus of the anti-human GPC3 VHH is linked directly or via a linker to the N- terminus of the CD28 hinge region and the CD28 transmembrane domain. The CAR further comprises a FCεR1γ intracellular T cell signaling domain. The C-terminus of the 10 CD28 transmembrane domain is linked directly or via a linker to the FCεR1γ intracellular T cell signaling domain. In one instance, the anti-human GPC3 VHH comprises a VHH- CDR1, a VHH-CDR2, and a VHH-CDR3 of SEQ ID NO:2. In some instances, the anti-human GPC3 VHH comprises an amino acid sequence that binds human GPC3 and is at least 80%, at least 85%, at least 90%, at least 91%, at 15 least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% identical to the amino acid sequence of SEQ ID NO:2, 150, or 151. In some cases, the anti-human GPC3 VHH binds human GPC3 and comprises an amino acid sequence that is identical to the amino acid sequence of SEQ ID NO:2, 150, or 151 except for 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions. In certain cases, 20 the substitutions are conservative amino acid substitutions. In certain instances, the CD28 hinge region and the CD28 transmembrane domain comprises an amino acid sequence that is at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% identical to the amino acid sequence of SEQ ID NO:3. 25 In some cases, the CD28 hinge region and the CD28 transmembrane domain comprises an amino acid sequence that is identical to the amino acid sequence of SEQ ID NO:3 except for 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions. In certain cases, the substitutions are conservative amino acid substitutions. 3 Attorney Docket No.: 45817-0177WO1 / MTX980.20 In some instances, the FCεR1γ intracellular T cell signaling domain comprises an amino acid sequence that is at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% identical to the amino acid sequence of SEQ ID NO:4. In some cases, 5 the FCεR1γ intracellular T cell signaling domain comprises an amino acid sequence that is identical to the amino acid sequence of SEQ ID NO:4 except for 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions. In certain cases, the substitutions are conservative amino acid substitutions. In certain instances, the CAR binds human GPC3 and comprises an amino acid 10 sequence that is at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to the amino acid sequence of SEQ ID NO:5. In some cases, the CAR binds human GPC3 and comprises an amino acid sequence that is identical to the amino acid sequence of SEQ ID NO:5 except for 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid 15 substitutions. In certain cases, the substitutions are conservative amino acid substitutions. In some instances, the CAR further comprises a signal peptide. In certain instances, the CAR binds human GPC3 and comprises an amino acid sequence that is at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 20 99% identical to the amino acid sequence of SEQ ID NO:6. In some cases, the CAR binds human GPC3 and comprises an amino acid sequence that is identical to the amino acid sequence of SEQ ID NO:6 except for 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions. In certain cases, the substitutions are conservative amino acid substitutions. In one instance, the CAR comprises or consists of the amino acid sequence of 25 SEQ ID NO:5. In another instance, the CAR comprises or consists of the amino acid sequence of SEQ ID NO:6. In another aspect, the disclosure features a messenger RNA (mRNA) comprising an open reading frame (ORF) encoding a CAR described herein. 4 Attorney Docket No.: 45817-0177WO1 / MTX980.20 In some instances, the ORF encodes a CAR that binds human GPC3 and is at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% identical to the nucleic acid sequence set forth in SEQ ID NO:8 or SEQ ID NO:9. 5 In certain instances, the ORF comprises the nucleic acid sequence set forth in SEQ ID NO:8. In another instance, the ORF comprises the nucleic acid sequence set forth in SEQ ID NO:9. In some instances, the mRNA further comprises a 5′ untranslated region (UTR) 10 comprising the nucleic acid sequence of SEQ ID NO:56. In other instances, the mRNA further comprises a 5′ untranslated region (UTR) comprising the nucleic acid sequence of SEQ ID NO:7. In certain instances, the mRNA further comprises a 3′ UTR comprising the nucleic acid sequence of any one of SEQ ID NOs:10 to 12 or 141. In one instance, the 3′ 15 UTR comprises the nucleic acid sequence of SEQ ID NO:141. In some instances, the mRNA comprises a 5′ terminal cap. In certain cases, the 5′ terminal cap comprises a m⁷GpppG2_^OMe, m7G-ppp-Gm-A, m7G-ppp-Gm-AG, Cap0, Cap1, ARCA, inosine, N1-methyl-guanosine, 2′-fluoro-guanosine, 7-deaza-guanosine, 8- oxo-guanosine, 2-amino-guanosine, LNA-guanosine, 2-azidoguanosine, Cap2, Cap4, 5′20 methylG cap, or an analog thereof, optionally wherein the terminal cap comprises m7G- ppp-Gm. In one embodiment, the 5’ terminal cap comprises m7G-ppp-Gm. In certain instances, the mRNA comprises a poly A region. In some cases, the poly A region is at least about 10, at least about 20, at least about 30, at least about 40, at least about 50, at least about 60, at least about 70, at least about 80, at least about 90 25 nucleotides in length, or at least about 100 nucleotides in length. In other cases, the poly A region is at least about 100 nucleotides in length (SEQ ID NO:117). In one case, the poly A-region comprises the sequence set forth in SEQ ID NO:13. In another case, the poly A-region comprises the sequence set forth in SEQ ID NO:117. In some instances, all of the uridines of the mRNA are N1 methylpseudouridines. 5 Attorney Docket No.: 45817-0177WO1 / MTX980.20 In other instances, all of the uridines in the mRNA are 5-methoxyuridines. In another aspect, the disclosure features an mRNA encoding a human GPC3 binding CAR, wherein the mRNA comprises a nucleic acid sequence that is at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at 5 least 97%, at least 98%, at least 99%, or 100% identical to any one of the sequences set forth in SEQ ID NOs.: 250, 251, 252, or 253. In one instance, the mRNA comprises the sequence set forth in any one of SEQ ID NOs: 250, 251, 252, or 253. In another instance, the mRNA comprises the sequence set forth in SEQ ID NO:253. In another aspect, the disclosure provides a polynucleotide comprising an mRNA 10 nucleotide sequence encoding a GPC3 binding CAR protein, comprising from 5′ to 3′ end: (i) a 5′ cap, optionally which comprises m⁷Gp-ppGm or m⁷Gp-ppGm-A or m⁷Gp-ppGm-AG; (ii) a 5′ UTR, optionally which comprises the nucleotide sequence set forth in 15 SEQ ID NO: 7 or 56; (iii) an open reading frame encoding a GPC3 binding CAR polypeptide comprising a nucleotide sequence set forth in SEQ ID NO:8 or 9; (iv) a 3′ UTR, optionally which comprises a nucleotide sequence set forth in any one of SEQ ID NOs:10 to 12 or 141; and 20 (v) a poly A tail, optionally which is of about 100 nt in length (SEQ ID NO:117), and further optionally which comprises optionally which comprises the nucleotide sequence set forth in SEQ ID NO:13 or 117. In one aspect, the disclosure features a polynucleotide comprising an mRNA nucleotide sequence encoding a GPC3 binding CAR protein, wherein the mRNA 25 sequence comprises or consists of any one of the sequences set forth in SEQ ID NOs.: 200, or 203 to 205. In another aspect, the disclosure features a polynucleotide comprising an mRNA nucleotide sequence encoding a GPC3 binding CAR protein, wherein the mRNA 6 Attorney Docket No.: 45817-0177WO1 / MTX980.20 sequence comprises or consists of any one of the sequences set forth in SEQ ID NOs.: 201 or 206. In yet another aspect, the disclosure features a polynucleotide comprising an mRNA nucleotide sequence encoding a GPC3 binding CAR protein, wherein the mRNA 5 sequence comprises or consists of any one of the sequences set forth in SEQ ID NOs.: 202 or 207. In another aspect, the disclosure features a pharmaceutical composition comprising an mRNA or polynucleotide described herein, and a pharmaceutically acceptable excipient. 10 In another aspect, the disclosure provides a pharmaceutical composition that comprises means for encoding a GPC3 binding CAR protein, and a pharmaceutically acceptable excipient. In yet another aspect, the disclosure relates to a lipid nanoparticle comprising an mRNA or polynucleotide described herein. In some cases, the lipid nanoparticle 15 comprises an ionizable amino lipid, a structural lipid, a phospholipid, and a polyethylene glycol (PEG)-modified lipid. In certain cases, the ionizable lipid is Compound II or a salt thereof. In some cases, the structural lipid is cholesterol. In certain cases, the phospholipid is 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) (Compound IV) or 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE). In some cases, the PEG- 20 modified lipid is PEG-DMG or Compound I. In one case, the ionizable lipid is Compound II or a salt thereof, the structural lipid is cholesterol, the phospholipid is 1,2- distearoyl-sn-glycero-3-phosphocholine (DSPC) or 1,2-dioleoyl-sn-glycero-3- phosphoethanolamine (DOPE), and the PEG-modified lipid is PEG-DMG or Compound I. 25 In one instance, the lipid nanoparticle comprises an ionizable amino lipid, a structural lipid, a phospholipid, and a polyethylene glycol (PEG)-modified lipid. In some cases, the delivery vehicle comprises Compound II, Compound I, Compound IV, and Cholesterol. In certain cases, the delivery vehicle comprises Compound II, PEG-DMG, Compound IV, and Cholesterol. In other cases, the delivery vehicle comprises Compound 7 Attorney Docket No.: 45817-0177WO1 / MTX980.20 III, Compound I, Compound V, and Cholesterol. In other cases, the delivery vehicle is referred to as “LNP9” and comprises Compound III, Compound IV, Cholesterol, Compound I, and Compound V. In yet other cases, the delivery vehicle is referred to as “LNP1” and comprises Compound II, IV, PEG-DMG, and cholesterol. 5 In one instance, the ionizable amino lipid is heptadecan-9-yl 8-((2- hydroxyethyl)(8-(nonyloxy)-8-oxooctyl)amino)octanoate and has the formula of Compound II of this disclosure. Compound III is 3-butylheptyl 8-((8-(heptadecan-9-yloxy)-8-oxooctyl)(2- hydroxyethyl)amino)octanoate and has the following formula: HO O N O 10 . Comp 3,6,9,12,15,18,21,24,27,30,33,36,39,42,45,48,51,54,57,60,63,66,69,72,75,78,81,84,87,90, 93,96,99,102,105,108,111,114,117,120,123,126,129,132- tetratetracontaoxatetratriacontahectyl stearate and has the following formula: 15 . Compound IV is 1,2-distearoyl-sn-glycero-3-phosphocholine and has the following structure: Attorney Docket No.: 45817-0177WO1 / MTX980.20 Compound V is 1,2-dimyristoyl-sn-glycero-3-phospho-L-serine (sodium salt) and has the following structure: 5 encoding a GPC3 binding CAR protein and a LNP comprising an ionizable amino lipid, a structural lipid, a phospholipid, and a polyethylene glycol (PEG)-modified lipid. In some cases, the LNP is “LNP9”. In other cases, the LNP is “LNP1”. In a preferred embodiment, the LNP is “LNP2”, which has been shown to be well tolerated and effective for delivering mRNA constructs in humans. 10 In another aspect, the disclosure provides a method for treating a cancer in a human subject in need thereof. The method comprises administering to the human subject an effective amount of an mRNA, polynucleotide, pharmaceutical composition, or lipid nanoparticle described herein. In some cases, the cancer is a GPC3+ solid tumor.  In some cases, the cancer is selected from the group consisting of Hepatocellular Carcinoma 15 (HCC) such as relapsed or refractory HCC, pancreatic cancer such as PDAC, breast cancer, a squamous cell lung cancer, a head and neck squamous cell cancer, and a lung squamous cell carcinoma (LSCC). In certain cases, the administering is performed intravenously. In some cases, administering is once a week, twice a week, three times a week, once every two weeks, once every three weeks, or once every four weeks. In one 20 instance the human subject is administered an effective amount of an mRNA comprising the sequence of SEQ ID NO:205 formulated in LNP2. In some instances, the method further comprises administering a checkpoint inhibitor. In some cases, the checkpoint inhibitor is a PD-1 inhibitor, a PD-LI inhibitor, a CTLA-4 inhibitor, a LAG-3 inhibitor, or a CISH inhibitor. In certain cases, the 25 checkpoint inhibitor is administered as a protein or as an mRNA. In certain cases, the 9 Attorney Docket No.: 45817-0177WO1 / MTX980.20 mRNA is formulated in an LNP. In one instance, the LNP is LNP1. In another instance, the LNP is LNP9. In some instances, the method further comprises administering an accessory molecule. In some cases, the accessory molecule is CD40L. 5 In another aspect, the disclosure features a CAR comprising means for binding human GPC3, a CD28 hinge region and a CD28 transmembrane domain, and a FCεR1γ intracellular T cell signaling domain. The CD28 transmembrane region is located at the C-terminus of the CD28 hinge region. The C-terminus of the means for binding human GPC3 is linked directly or via a linker to the CD28 hinge region and the CD28 10 transmembrane domain. The C-terminus of the CD28 transmembrane domain is linked directly or via a linker to the FCεR1γ intracellular T cell signaling domain. In a further aspect, the disclosure features a mRNA or polynucleotide encoding the CAR described above and methods of using the CAR or the mRNA or polynucleotide encoding the CAR for treating a cancer such as Hepatocellular Carcinoma (HCC) in a 15 human subject in need thereof. In some cases, the HCC is relapsed HCC or refractory HCC. BRIEF DESCRIPTION OF DRAWINGS FIG.1 are representative schematic diagrams of the CAR architecture. All CARs 20 contain CD28 hinge and transmembrane regions and Fc gamma intracellular domain (Gene ID: FCER1G). The binding domains comprise anti-GPC3 variable domains of heavy-chain antibodies (VHHs). Construct 1 comprises the VHH set forth in SEQ ID NO:2; Construct 2 comprises the VHH set forth in SEQ ID NO:150; and Construct 3 comprises the VHH set forth in SEQ ID NO:151. 25 FIG.2 is series of graphs depicting cell viability and binding to soluble GPC3 by human macrophages transfected with various anti-GPC3-CAR mRNA/LNPs. In this case the mRNA was formulated in LNP2. 10 Attorney Docket No.: 45817-0177WO1 / MTX980.20 FIG.3 is series of graphs depicting killing of GPC3 expressing tumor cell lines (HEPG2, HUH7, and HEP3B) by human macrophages transfected with various anti- GPC3-CAR mRNA/LNPs. In this case the mRNA was formulated in LNP2.. FIG.4 is series of graphs depicting secretion of proinflammatory cytokines 5 (TNF⍺, IL-6, IL-1β, and IFN^^) in response to immobilized GPC3 by human macrophages transfected with various anti-GPC3-CAR mRNA/LNPs. In this case the mRNA was formulated in LNP2.. FIG.5 contains (i) a graph depicting tumor burden in mice after treatment with anti-GPC3-CAR mRNA/LNP encoding Construct 1 (SEQ ID NO:200) or Construct 4 10 (SEQ ID NO:203), and (ii) ex vivo bioluminescence imaging of the livers of treated mice. In this case the mRNA was formulated in LNP2.. FIG.6 contains (i) a graph depicting tumor burden in mice after treatment with anti-GPC3-CAR mRNA/LNP encoding Construct 1 or Construct 4, (ii) ex vivo bioluminescence imaging of the livers of treated mice, (iii) histology of the livers of 15 treated mice, and (iv) a graph depicting GPC3+ lesions in the livers of treated mice. In this case the mRNA was formulated in LNP2.. FIG.7 contains (i) a graph depicting tumor burden in mice using a Panc-1 hGPC3 hCD34+ model after treatment with anti-GPC3-CAR mRNA/LNP encoding Construct 4, and (ii) ex vivo bioluminescence imaging of the livers of treated mice. In this case the 20 mRNA was formulated in LNP2.. FIG.8 contains (i) a graph depicting tumor burden in mice after treatment with anti-GPC3-CAR mRNA/LNP encoding Construct 4, (ii) ex vivo bioluminescence imaging of the livers of treated mice, and (iii) a graph depicting body weights of treated mice. In this case the mRNA was formulated in LNP2.. 25 FIG.9 shows CAR expression analyzed in various populations of tumor infiltrating immune cells harvested from subcutaneous tumors of Panc-1 hGPC3 hCD34+ mice. mRNA constructs formulated in both LNP9 and LNP1 showed high levels of CAR expression in lymphocytes, regardless of the construct tested (Figure 9, right panel). 11 Attorney Docket No.: 45817-0177WO1 / MTX980.20 FIG.10 shows CAR expression analyzed in various populations of immune cells infiltrating the livers of treated Panc-1 hGPC3 hCD34+ mice. In this study, LNP9 containing Construct 4 showed the highest expression in liver macrophages and LNP1 containing this construct also showed good expression. 5 FIG.11 shows tumor growth and CAR expression in mice bearing PANC1_hGPC3 after injection with anti-GPC3-CAR mRNA/LNP encoding Construct 1 or Construct 4. mRNA constructs formulated in both LNP 1 and LNP 2 were tested in this study and both showed reduction in tumor growth. FIG.12A shows that engineering human macrophages with anti-GPC3 CAR 10 mRNA/LNP led to titratable anti-GPC3 CAR expression on day 1. In all sections of this Figure the mRNA was formulated in LNP2.. FIG.12B shows that engineering human macrophages with anti-GPC3 CAR mRNA/LNP led to titratable rGPC3 binding on day 1. FIG.12C shows that anti-GPC3 CAR-M exhibits cytotoxicity against HEPG2 15 target cells that positively correlates with CAR expression (Spearman r:0.8531, p-value: 0.0008). FIG.13 shows that human macrophages expressing anti-GPC3 CAR are highly specific to GPC3 antigen. FIG.14A shows the kinetics and dose-dependent expression of anti-GPC3 CAR 20 after transfection with 9 nM of anti-GPC3 CAR mRNA/LNP in vitro. In all sections of this Figure the mRNA was formulated in LNP2.. FIG.14B shows the kinetics and dose-dependent expression of anti-GPC3 CAR after transfection with increasing concentration of anti-GPC3 CAR mRNA/LNP in vitro. FIG.14C shows potent anti-GPC3 CAR-M killing against HEPG2 cells on day 1 25 post-transfection at E:T=4:1. FIG.14D shows potent anti-GPC3 CAR-M killing against HEPG2 cells on day 7 post-transfection at E:T=4:1. FIG.15A shows that the level of soluble GPC3 increases as the stage of disease increases. 12 Attorney Docket No.: 45817-0177WO1 / MTX980.20 FIG.15B shows that sGPC3 blocks the interaction of CAR-expressing macrophages with HEPG2 tumor cells in a dose-dependent manner. FIG.15C shows that macrophages with anti-GPC3 CAR mRNA formulated in LNP showed robust HEPG2 cell killing. sGPC3 inhibited CAR macrophage-killing 5 activity in a dose-dependent manner. FIG.16A provides the data of experiments wherein anti-GPC3 CAR-M cytotoxic activity was evaluated in vitro using HCC cell lines with endogenous GPC3 expression. FIG.16B provides the data of experiments wherein anti-GPC3 CAR-M cytotoxic activity was evaluated in vitro using HCC cell lines with endogenous GPC3 expression. 10 FIG.16C provides the data of experiments wherein anti-GPC3 CAR-M cytotoxic activity was evaluated in vitro using AU565 cells overexpressing different levels of surface human GPC3. FIG.16D shows that cytotoxicity, represented as area under the curve (AUC), positively correlates with target GPC3 expression. 15 FIG.17A shows that rGPC3 stimulation leads to dose-dependent pro- inflammatory TNF-α cytokine secretion by anti-GPC3 CAR-M. FIG.17B shows that rGPC3 stimulation leads to dose-dependent pro- inflammatory IL-8 cytokine secretion by anti-GPC3 CAR-M. FIG.17C shows that rGPC3 stimulation leads to dose-dependent pro- 20 inflammatory IL-6 cytokine secretion by anti-GPC3 CAR-M. FIG.18 shows that rGPC3 stimulation increases M1 (CD86) and decreases M2 (CD163, CD206) surface markers on anti-GPC3 CAR-M. FIG.19A shows the results of flow analysis demonstrating that anti-GPC3 CAR expression is primarily expressed in monocytes in the blood of C57BL/6 mice injected 25 with Construct 4 anti-GPC3 CAR-M mRNA/LNP. In all sections of this figure the mRNA was formulated in LNP2.. FIG.19B shows the results of flow analysis demonstrating that anti-GPC3 CAR expression is primarily expressed in monocytes in the blood of C57BL/6 mice injected with Construct 4 anti-GPC3 CAR-M mRNA formulated in LNP. 13 Attorney Docket No.: 45817-0177WO1 / MTX980.20 FIG.19C shows the results of flow analysis demonstrating that anti-GPC3 CAR expression is primarily expressed in myeloid cells in subcutaneous MC38_GPC3 tumors of C57BL/6 mice injected with Construct 4 anti-GPC3 CAR-M mRNA/LNP. (pMoncoytes = patrolling monocytes; iMonocytes = inflammatory monocytes.) 5 FIG.20A shows that twice weekly dosing of Construct 4 anti-GPC3 CAR mRNA/LNP in i.v. PANC-1_GPC3 engrafted CD34⁺ HSC humanized NSG-S mice inhibits tumor growth compared to NT mRNA/LNP (a negative control) as measured by whole body bioluminescence. In all sections of this figure the mRNA was formulated in LNP2.. 10 FIG.20B shows that weekly dosing of Construct 4 anti-GPC3 CAR mRNA/LNP in i.v. PANC-1_GPC3 engrafted CD34⁺ HSC humanized NSG-S mice inhibits tumor growth compared to NT mRNA/LNP as measured by whole body bioluminescence. FIG.20C shows the change in tumor burden at day 39 vs day 3 for weekly dosing of Construct 4 anti-GPC3 CAR mRNA/LNP in i.v. PANC-1_GPC3 engrafted CD34⁺ 15 HSC humanized NSG-S mice. FIG.20D shows that weekly dosing of Construct 8 anti-GPC3 CAR mRNA/LNP in i.v. PANC-1_GPC3 engrafted CD34⁺ HSC humanized NSG-S mice reduces tumor burden in the lung compared to NT mRNA/LNP. FIG.20E shows that weekly dosing of Construct 4 anti-GPC3 CAR mRNA/LNP 20 day 4 in i.v. PANC-1_GPC3 engrafted CD34⁺ HSC humanized NSG-S mice reduces tumor burden in the liver compared to NT mRNA/LNP. FIG.20F shows that weekly dosing of Construct 4 anti-GPC3 CAR mRNA/LNP in i.v. PANC-1_GPC3 engrafted CD34⁺ HSC humanized NSG-S mice reduces tumor burden in the liver compared to NT mRNA/LNP. 25 FIG.20G shows that weekly dosing of Construct 4 anti-GPC3 CAR mRNA/LNP in i.v. PANC-1_GPC3 engrafted CD34⁺ HSC humanized NSG-S mice reduces tumor burden in the liver compared to NT mRNA/LNP as measured by immunohistochemistry. FIG.21A shows that weekly dosing of Construct 4 anti-GPC3 CAR mRNA/LNP in i.v. PANC-1_GPC3 engrafted CD34⁺ HSC humanized NSG-S mice does not increase 14 Attorney Docket No.: 45817-0177WO1 / MTX980.20 the levels of serum biomarker for liver function Gamma-glutamyl Transferase. In all sections of this figure the mRNA was formulated in LNP2. FIG.21B shows that weekly dosing of Construct 4 anti-GPC3 CAR mRNA/LNP in i.v. PANC-1_GPC3 engrafted CD34⁺ HSC humanized NSG-S mice does not increase 5 the levels of serum biomarker for liver function Alanine Aminotransferase. FIG.21C shows that weekly dosing of Construct 4 anti-GPC3 CAR mRNA/LNP in i.v. PANC-1_GPC3 engrafted systemic intravenous delivery (five weekly doses) CD34⁺ HSC humanized NSG-S mice does not increase the levels of serum biomarker for liver function Aspartate Aminotransferase. 10 FIG.21D shows that weekly dosing of Construct 8 anti-GPC3 CAR mRNA/LNP in i.v. PANC-1_GPC3 engrafted CD34⁺ HSC humanized NSG-S mice does not increase the levels of serum biomarkers for liver and kidney function Blood Urea Nitrogen. FIG.21E shows that no adverse events or changes in body weight are observed in any groups in this study. 15 DETAILED DESCRIPTION Chimeric antigen receptor macrophage (CAR-M) cell therapies have the potential to mediate robust anti-tumor immunity via phagocytosis, cytokine/chemokine release, antigen presentation, activation of the tumor microenvironment (TME) and T cell 20 recruitment. Described herein is a novel off-the-shelf approach to directly reprogram endogenous myeloid cells in vivo by systemically delivering mRNA formulated in lipid nanoparticles (LNP), wherein the mRNA encodes CARs targeting glypican-3 (GPC3). GPC3 is a tumor-associated surface antigen that is overexpressed in hepatocellular carcinoma (HCC) with minimal expression on normal tissues. The CAR architecture 25 disclosed herein was optimized to maximize antigen-dependent myeloid activation. Anti-GPC3 CAR-M described herein have a high binding affinity to GPC3, and lack of binding to related glypican proteins. An anti-GPC3-CAR comprising a hinge, transmembrane, and signaling domain optimized for myeloid cells demonstrated enhanced antigen-dependent macrophage activation without tonic signaling. Functional 15 Attorney Docket No.: 45817-0177WO1 / MTX980.20 evaluation demonstrated CAR expression on human macrophages for more than 7 days in vitro leading to dose-dependent cytotoxicity against multiple GPC3+ tumor lines. At physiologic levels, soluble GPC3 did not interfere with the cytotoxic activity of anti- GPC3 CAR-M. In humanized immune system mice with disseminated GPC3+ solid 5 tumors, systemic administration of anti-GPC3 CAR LNP/mRNA led to robust anti-tumor activity and suppressed tumor lesions in the liver. Myeloid cells were the primary CAR+ cells after systemic LNP administration. Treated animals tolerated repeat mRNA/LNP administration with no significant elevation in plasma cytokine levels or other signs of toxicity. 10 These data demonstrate that anti-GPC3 CAR-M can be directly produced in vivo utilizing mRNA/LNP, reducing tumor burden in translationally relevant humanized solid tumor models. In vivo CAR-M represents a novel off-the-shelf cell therapy strategy for patients with GPC3+ solid tumors, including HCC. Provided herein are polypeptides and nucleic acids (e.g., mRNA) for GPC3 (e.g., 15 human GPC3) binding chimeric antigen rectors (CARs) These GPC3 CARs can be used in the treatment of any diseases or disorder with abnormal expression of GPC3. In certain instances, these GPC3 CARs are useful in treating GPC3 positive cancers or tumors. Definitions 20 As used herein, the term “about” refers to a stated numerical term and a value that is no more than 10% above or below the value being described. For example, the term “about 5 nM” indicates disclosure of both the stated value of 5 nM and a range of from 4.5 nM to 5.5 nM. When used with respect to time, e.g., “about” 1 week, the term “about” means +/- 3 days, so about 1 week refers to 1 week and a range of 4 days to 10 25 days. As used herein, the terms “conservative mutation,” “conservative substitution,” “conservative amino acid substitution,” and the like refer to a substitution of one or more amino acids for one or more different amino acids that exhibit similar physicochemical 16 Attorney Docket No.: 45817-0177WO1 / MTX980.20 properties, such as polarity, electrostatic charge, and/or steric volume. These properties are summarized for each of the twenty naturally-occurring amino acids in Table 1 below. Table 1 – Representative Physicochemical Properties of Naturally-Occurring Amino Acids 3 1 Side- Electrostatic Amino Acid Letter Letter chain character at Steric e e e e e e e e 5 From this table it is appreciated that the conservative amino acid families include, e.g., (i) G, A, V, L, I, P, and M; (ii) D and E; (iii) C, S and T; (iv) H, K and R; (v) N and Q; and (vi) F, Y and W. A conservative mutation or substitution is therefore one that 17 Attorney Docket No.: 45817-0177WO1 / MTX980.20 substitutes one amino acid for a member of the same amino acid family (e.g., a substitution of Ser for Thr or Lys for Arg). As used herein, the term “fusion protein” refers to a protein that is joined via a covalent bond to another molecule. 5 As used herein, the term “lipid nanoparticle” refers to a transfer vehicle including one or more lipids (e.g., cationic lipids, non-cationic lipids, and PEG-modified lipids). Examples of lipid nanoparticles are formulated to deliver one or more mRNA to one or more target cells. Examples of suitable lipids include, for example, the phosphatidyl compounds (e.g., phosphatidylglycerol, phosphatidylcholine, phosphatidylserine, 10 phosphatidylethanolamine, sphingolipids, cerebrosides, and gangliosides). Lipid nanoparticles may contain a cationic lipid, or a lipid species with a net positive charge at a selected pH (e.g., physiological pH), to enhance the delivery of mRNA into the target cells. As used herein, the terms “percent (%) sequence identity,” “percent (%) identity,” 15 and the like, with respect to a reference polynucleotide or polypeptide sequence, is defined as the percentage of nucleic acids or amino acids in a candidate sequence that are identical to the nucleic acids or amino acids in the reference polynucleotide or polypeptide sequence, after aligning the sequences and introducing gaps, if necessary, to achieve the maximum percent sequence identity. Alignment for purposes of determining 20 percent nucleic acid or amino acid sequence identity can be achieved in various ways that are within the capabilities of one of skill in the art, for example, using publicly available computer software such as BLAST, BLAST-2, or Megalign software. Those skilled in the art can determine appropriate parameters for aligning sequences, including any algorithms needed to achieve maximal alignment over the full length of the sequences 25 being compared. For example, percent sequence identity values may be generated using the sequence comparison computer program BLAST. As an illustration, the percent sequence identity of a given nucleic acid or amino acid sequence, A, to, with, or against a given nucleic acid or amino acid sequence, B, (which can alternatively be phrased as a given nucleic acid or amino acid sequence, A that has a certain percent sequence identity 18 Attorney Docket No.: 45817-0177WO1 / MTX980.20 to, with, or against a given nucleic acid or amino acid sequence, B) is calculated as: 100 multiplied by (the fraction X/Y) where X is the number of nucleotides or amino acids scored as identical matches by a sequence alignment program (e.g., BLAST) in that program’s alignment of A and B, and where Y is the total number of nucleic acids in B. 5 It will be appreciated that where the length of nucleic acid or amino acid sequence A is not equal to the length of nucleic acid or amino acid sequence B, the percent sequence identity of A to B will not equal the percent sequence identity of B to A. As used herein, the phrase “specifically binds” refers to a binding reaction which is determinative of the presence of an antigen in a heterogeneous population of proteins 10 and other biological molecules that is recognized, e.g., by an antibody or antigen-binding fragment thereof, with particularity. An antibody or antigen-binding fragment thereof that specifically binds to an antigen will bind to the antigen with a KD of less than 100 nM. For example, an antibody or antigen-binding fragment thereof that specifically binds to an antigen via the antigen binding domain will bind to the antigen with a KD of up to 15 100 nM (e.g., between 1 pM and 100 nM). An antibody or antigen-binding fragment thereof that does not exhibit specific binding to a particular antigen or epitope thereof will exhibit a K_D of greater than 100 nM (e.g., greater than 500 nm, 1 µM, 100 µM, 500 µM, or 1 mM) for that particular antigen or epitope thereof. A variety of immunoassay formats may be used to select antibodies specifically immunoreactive with a particular 20 protein or carbohydrate. For example, solid-phase ELISA immunoassays are routinely used to select antibodies specifically immunoreactive with a protein or carbohydrate. See, Harlow & Lane, Antibodies, A Laboratory Manual, Cold Spring Harbor Press, New York (1988) and Harlow & Lane, Using Antibodies, A Laboratory Manual, Cold Spring Harbor Press, New York (1999), for a description of immunoassay formats and 25 conditions that can be used to determine specific immunoreactivity. As used herein, the terms “treat” or “treatment” refer to therapeutic treatment, in which the object is to inhibit or slow down (lessen) an undesired physiological change or disorder, such as a cancer or an immunological disorder (e.g., autoimmune disorders (e.g., allograft rejection) and graft-versus-host disease, among others). Beneficial or 19 Attorney Docket No.: 45817-0177WO1 / MTX980.20 desired clinical results of treatment include, without limitation, alleviation of symptoms, diminishment of extent of disease, stabilized (i.e., not worsening) state of disease, delay or slowing of disease progression, amelioration or palliation of the disease state, and remission (whether partial or total), whether detectable or undetectable. Those in need of 5 treatment include those already having the condition or disorder, as well as those prone to have the condition or disorder or those in which the condition or disorder is to be inhibited. As used herein, the term “alkyl,” “alkyl group,” or “alkylene” means a linear or branched, saturated hydrocarbon including one or more carbon atoms (e.g., one, two, 10 three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, nineteen, twenty, or more carbon atoms), which is optionally substituted. The notation “C1-14 alkyl” means an optionally substituted linear or branched, saturated hydrocarbon including 1-14 carbon atoms. Unless otherwise specified, an alkyl group described herein refers to both unsubstituted and substituted 15 alkyl groups. As used herein, the term “alkenyl,” “alkenyl group,” or “alkenylene” means a linear or branched hydrocarbon including two or more carbon atoms (e.g., two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, nineteen, twenty, or more carbon atoms) and at least one double 20 bond, which is optionally substituted. The notation “C₂-₁₄ alkenyl” means an optionally substituted linear or branched hydrocarbon including 2-14 carbon atoms and at least one carbon-carbon double bond. An alkenyl group may include one, two, three, four, or more carbon-carbon double bonds. For example, C₁₈ alkenyl may include one or more double bonds. A C18 alkenyl group including two double bonds may be a linoleyl group. Unless 25 otherwise specified, an alkenyl group described herein refers to both unsubstituted and substituted alkenyl groups. As used herein, the term “alkynyl,” “alkynyl group,” or “alkynylene” means a linear or branched hydrocarbon including two or more carbon atoms (e.g., two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, sixteen, 20 Attorney Docket No.: 45817-0177WO1 / MTX980.20 seventeen, eighteen, nineteen, twenty, or more carbon atoms) and at least one carbon- carbon triple bond, which is optionally substituted. The notation “C2-14 alkynyl” means an optionally substituted linear or branched hydrocarbon including 2-14 carbon atoms and at least one carbon-carbon triple bond. An alkynyl group may include one, two, 5 three, four, or more carbon-carbon triple bonds. For example, C18 alkynyl may include one or more carbon-carbon triple bonds. Unless otherwise specified, an alkynyl group described herein refers to both unsubstituted and substituted alkynyl groups. As used herein, the term “carbocycle” or “carbocyclic group” means an optionally substituted mono- or multi-cyclic system including one or more rings of carbon atoms. 10 Rings may be three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, nineteen, or twenty membered rings. The notation “C3-6 carbocycle” means a carbocycle including a single ring having 3-6 carbon atoms. Carbocycles may include one or more carbon-carbon double or triple bonds and may be non-aromatic or aromatic (e.g., cycloalkyl or aryl groups). Examples of 15 carbocycles include cyclopropyl, cyclopentyl, cyclohexyl, phenyl, naphthyl, and 1,2 dihydronaphthyl groups. The term “cycloalkyl” as used herein means a non-aromatic carbocycle and may or may not include any double or triple bond. Unless otherwise specified, carbocycles described herein refers to both unsubstituted and substituted carbocycle groups, i.e., optionally substituted carbocycles. 20 As used herein, the term “heterocycle” or “heterocyclic group” means an optionally substituted mono- or multi-cyclic system including one or more rings, where at least one ring includes at least one heteroatom. Heteroatoms may be, for example, nitrogen, oxygen, or sulfur atoms. Rings may be three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, or fourteen membered rings. Heterocycles may include one 25 or more double or triple bonds and may be non-aromatic or aromatic (e.g., heterocycloalkyl or heteroaryl groups). Examples of heterocycles include imidazolyl, imidazolidinyl, oxazolyl, oxazolidinyl, thiazolyl, thiazolidinyl, pyrazolidinyl, pyrazolyl, isoxazolidinyl, isoxazolyl, isothiazolidinyl, isothiazolyl, morpholinyl, pyrrolyl, pyrrolidinyl, furyl, tetrahydrofuryl, thiophenyl, pyridinyl, piperidinyl, quinolyl, and 21 Attorney Docket No.: 45817-0177WO1 / MTX980.20 isoquinolyl groups. The term “heterocycloalkyl” as used herein means a non-aromatic heterocycle and may or may not include any double or triple bond. Unless otherwise specified, heterocycles described herein refers to both unsubstituted and substituted heterocycle groups, i.e., optionally substituted heterocycles. 5 As used herein, the term “heteroalkyl,” “heteroalkenyl,” or “heteroalkynyl” refers respectively to an alkyl, alkenyl, alkynyl group, as defined herein, which further comprises one or more (e.g., 1, 2, 3, or 4) heteroatoms (e.g., oxygen, sulfur, nitrogen, boron, silicon, phosphorus) wherein the one or more heteroatoms is inserted between adjacent carbon atoms within the parent carbon chain and/or one or more heteroatoms is 10 inserted between a carbon atom and the parent molecule, i.e., between the point of attachment. Unless otherwise specified, heteroalkyls, heteroalkenyls, or heteroalkynyls described herein refers to both unsubstituted and substituted heteroalkyls, heteroalkenyls, or heteroalkynyls, i.e., optionally substituted heteroalkyls, heteroalkenyls, or heteroalkynyls. 15 As used herein, a “biodegradable group” is a group that may facilitate faster metabolism of a lipid in a mammalian entity. A biodegradable group may be selected from the group consisting of, but is not limited to, -C(O)O-, -OC(O)-, -C(O)N(R')-, - N(R')C(O)-, -C(O)-, -C(S)-, -C(S)S-, -SC(S)-, -CH(OH)-, -P(O)(OR')O-, -S(O)2-, an aryl group, and a heteroaryl group. As used herein, an “aryl group” is an optionally 20 substituted carbocyclic group including one or more aromatic rings. Examples of aryl groups include phenyl and naphthyl groups. As used herein, a “heteroaryl group” is an optionally substituted heterocyclic group including one or more aromatic rings. Examples of heteroaryl groups include pyrrolyl, furyl, thiophenyl, imidazolyl, oxazolyl, and thiazolyl. Both aryl and heteroaryl groups may be optionally substituted. For 25 example, M and M' can be selected from the non-limiting group consisting of optionally substituted phenyl, oxazole, and thiazole. In the Formulas herein, M and M' can be independently selected from the list of biodegradable groups above. Unless otherwise specified, aryl or heteroaryl groups described herein refers to both unsubstituted and substituted groups, i.e., optionally substituted aryl or heteroaryl groups. 22 Attorney Docket No.: 45817-0177WO1 / MTX980.20 Alkyl, alkenyl, and cyclyl (e.g., carbocyclyl and heterocyclyl) groups may be optionally substituted unless otherwise specified. Optional substituents may be selected from the group consisting of, but are not limited to, a halogen atom (e.g., a chloride, bromide, fluoride, or iodide group), a carboxylic acid (e.g., C(O)OH), an alcohol (e.g., a 5 hydroxyl, OH), an ester (e.g., C(O)OR OC(O)R), an aldehyde (e.g., C(O)H), a carbonyl (e.g., C(O)R, alternatively represented by C=O), an acyl halide (e.g., C(O)X, in which X is a halide selected from bromide, fluoride, chloride, and iodide), a carbonate (e.g., OC(O)OR), an alkoxy (e.g., OR), an acetal (e.g., C(OR)2R"", in which each OR are alkoxy groups that can be the same or different and R"" is an alkyl or alkenyl group), a 10 phosphate (e.g., P(O)₄ ^3-), a thiol (e.g., SH), a sulfoxide (e.g., S(O)R), a sulfinic acid (e.g., S(O)OH), a sulfonic acid (e.g., S(O)2OH), a thial (e.g., C(S)H), a sulfate (e.g., S(O)4^2-), a sulfonyl (e.g., S(O)2 ), an amide (e.g., C(O)NR2, or N(R)C(O)R), an azido (e.g., N₃), a nitro (e.g., NO₂), a cyano (e.g., CN), an isocyano (e.g., NC), an acyloxy (e.g., OC(O)R), an amino (e.g., NR2, NRH, or NH2), a carbamoyl (e.g., OC(O)NR2, 15 OC(O)NRH, or OC(O)NH2), a sulfonamide (e.g., S(O)2NR2, S(O)2NRH, S(O)2NH2, N(R)S(O)₂R, N(H)S(O)₂R, N(R)S(O)₂H, or N(H)S(O)₂H), an alkyl group, an alkenyl group, and a cyclyl (e.g., carbocyclyl or heterocyclyl) group. In any of the preceding, R is an alkyl or alkenyl group, as defined herein. In some embodiments, the substituent groups themselves may be further substituted with, for example, one, two, three, four, 20 five, or six substituents as defined herein. For example, a C_1-6 alkyl group may be further substituted with one, two, three, four, five, or six substituents as described herein. Compounds of the disclosure that contain nitrogens can be converted to N-oxides by treatment with an oxidizing agent (e.g., 3-chloroperoxybenzoic acid (mCPBA) and/or hydrogen peroxides) to afford other compounds of the disclosure. Thus, all shown and 25 claimed nitrogen-containing compounds are considered, when allowed by valency and structure, to include both the compound as shown and its N-oxide derivative (which can be designated as N^O or N+-O-). Furthermore, in other instances, the nitrogens in the compounds of the disclosure can be converted to N-hydroxy or N-alkoxy compounds. For example, N-hydroxy compounds can be prepared by oxidation of the parent amine by 23 Attorney Docket No.: 45817-0177WO1 / MTX980.20 an oxidizing agent such as m CPBA. All shown and claimed nitrogen-containing compounds are also considered, when allowed by valency and structure, to cover both the compound as shown and its N-hydroxy (i.e., N-OH) and N-alkoxy (i.e., N-OR, wherein R is substituted or unsubstituted C1-C6 alkyl, C1-C6 alkenyl, C1-C6 alkynyl, 3-14-membered 5 carbocycle or 3-14-membered heterocycle) derivatives. Anti-GPC3 Binding Polypeptides Glypican 3” or “GPC3” refers to a cell surface heparan sulfate proteoglycan 10 comprising a membrane-associated protein core substituted with a variable number of heparan sulfate chains. The GPC3 protein is important in cellular signaling and modulates a plurality of cellular functions, including, for example, cell growth, embryogenesis, and differentiation. The amino acid sequence of human GPC3 is provided below: 15 MAGTVRTACLVVAMLLSLDFPGQAQPPPPPPDATCHQVRSFFQRLQPGLKWVPE TPVPGSDLQVCLPKGPTCCSRKMEEKYQLTARLNMEQLLQSASMELKFLIIQNA AVFQEAFEIVVRHAKNYTNAMFKNNYPSLTPQAFEFVGEFFTDVSLYILGSDINV DDMVNELFDSLFPVIYTQLMNPGLPDSALDINECLRGARRDLKVFGNFPKLIMTQ VSKSLQVTRIFLQALNLGIEVINTTDHLKFSKDCGRMLTRMWYCSYCQGLMMV 20 KPCGGYCNVVMQGCMAGVVEIDKYWREYILSLEELVNGMYRIYDMENVLLGLF STIHDSIQYVQKNAGKLTTTIGKLCAHSQQRQYRSAYYPEDLFIDKKVLKVAHVE HEETLSSRRRELIQKLKSFISFYSALPGYICSHSPVAENDTLCWNGQELVERYSQK AARNGMKNQFNLHELKMKGPEPVVSQIIDKLKHINQLLRTMSMPKGRVLDKNL DEEGFESGDCGDDEDECIGGSGDGMIKVKNQLRFLAELAYDLDVDDAPGNSQQ 25 ATPKDNEISTFHNLGNVHSPLKLLTSMAISVVCFFFLVH (SEQ ID NO: 267) This disclosure features anti-GPC3 binding agents such as CARs comprising an anti-GPC3 binding polypeptide(s). In one instance, the GPC3 binding polypeptide is a VHH (also referred to as a single domain antibody). In some cases, the anti-GPC3 VHH binds to human GPC3. In some cases, the anti-GPC3 VHH binds to murine GPC3. In 24

⁰ ₂ ^. ₀ ^{e 8} ₉ ^d _{e g} ⁿ X ^d _{i a} ^r _e T ^v _o ^h M t ^M _/ ^r _p ⁿ ₁ O _e ^r _t ^{f i} _{o , g} ^a R i ₃ R _i ^{h W} _{a t} D ₇ ⁷ _{s d e} D ^o _h ^{C e} ₁ H ^{l 0} _g ^C- ^C - H _{, n} ^{o 7} ₁ V ⁿ _i H s H ^t _a ^{y 8} _{5 3} ^{e b} _n ⁴ C _v ^V _a ^af _: ^. P ^a _o ^{G N} _{- h} ^{a K} s ^d _n ^s _{o t} ^{i a} _{a 3} R Y ^e _{t k} ⁿ H ^c _a H ^, _{h 2} ^c _u D _{) 4 ) 5} DF⁾ ₆ ² _{o f} V R ^s _t ^{C r} - ² _: ² _: ^P _: H O O _PEO ^{D o} ₃ D _a A ^N T^{S N G N y} _e ^{s n} _e C ^C _{- e} H ^Y _{S S F r} ^{l o} _p P ^t G H ^h _t ^V D a T ^S _F ^I GD ^I RD P ^I _t ^m _a -_i H ^f _o ^d G TQ GQ FE GE DQE A ^x _e ^t _n ^{V a} _{n n} ^{a M} _I G^S ₍ ^S _I ^S ₍ R S^S _{( g} ^{a n ,} i _s ^{, e} ₁ ^o _i R ^t _i ^, ₂ R Y _{h y h} ^c _{o 8} t ^{b C} o ^d H - ^{c n} ₇ b _e ^t H H _a ¹ _: ¹ Y : ^D _{6 F} ¹ _: o _a H t ^r V H _. H _r ^o O O f ^{P Y N} _S ^N _PO N ^s _{o 3} ^V d ^{p n} _r ^e T V _s ^a _ih _S ^SD ^I SD ^I E GD ^I i ^o CP _h G ₃ n C ^{o t} _{o F} G TQ GQ _F RQ b _c ⁿ i ^G- T ^{M i} _I P _{. i} ^t _i h FE t _. ^S GE^S PE^{S 2} _{: r} ^{o G}- C G i ^{w n} _i ^f ₍ S ₍ D ₍ H ^s i ⁿ H ^h _{a , e} O ^t _{t o} ^l _e N _c ⁿ _{a e} ^{b D} G V _{c 3} ⁱ _h ^h t ^a C ^, D _t I ⁿ _{e o} ^h t A ² R KL D S P ^w ₍ ^. _s G ₃ ^e _c Q ^C _, ^, _{s - 2} i_t ³ C ⁿ _a E ^{e e} _l ^C D ) A^{) ) S o} _c ^b _a ^y _{r 4} ¹ Y₅ ¹ Y D₆ ^{1 n} _{7 a} ¹ P ^t 8 ^G _s ⁿ _h A ⁿ _a ^{T a} _{l :} Y O T_: O _{F : e} ^{0 n n} i i _, ^{t a} _s ^{n n} _i p ^{N S} _S ^{N P} _PO N ^h _{/ a t} ^{3 ,} _{s 2} ^{m n} _i ^{h a} _{t t} ^r _{i i o n} m ^t _SD f ^h _t ^I GD ^I E GD o _e w ^e _{x a} M G ^I Q Q _FQ e ⁰ _{u s 2} ^{h r a} S ^r _e ^{c t} _e ^s _h ^{m o C} _o ^s _h ^{s E b -} _a AE ^G _SE RPE K Y S^S ₍ ^I _S ^S ₍ D^S _{( c n} ^U _{/ o} ^{f n} _I ^{e i} T ^y a _t t ⁱ _c ^{d n} _e ⁿ _I ⁿ _{o e} ^c _n ⁱ A t^{i 2 e} _l - - - H H₁ R H₂ R H₃ R r C e ^P _n ⁱ _f ^u _q ^a _{h n} ⁱ _f ^b H HD HD HD c ⁿ _i ^f _a ^e _s ⁿ _e ^e _{d a} T V V C V C V C 5 ⁰ ₁ Attorney Docket No.: 45817-0177WO1 / MTX980.20 In some cases, the anti-GPC3 VHH comprises the VHH-CDR1, the VHH-CDR2, and the VHH-CDR3 sequences set forth in SEQ ID NOS.: 14, 15, and 16, respectively. In certain cases, the anti-GPC3 VHH comprises the VHH-CDR1, the VHH- CDR2, and the VHH-CDR3 sequences set forth in SEQ ID NOS.: 17, 18, and 16, 5 respectively. In some cases, the anti-GPC3 VHH comprises the VHH-CDR1, the VHH-CDR2, and the VHH-CDR3 sequences set forth in SEQ ID NOS.: 19, 20, and 16, respectively. In other cases, the anti-GPC3 VHH comprises the VHH-CDR1, the VHH-CDR2, and the VHH-CDR3 sequences set forth in SEQ ID NOS.: 21, 22, and 23, respectively. 10 In further cases, the anti-GPC3 VHH comprises the VHH-CDR1, the VHH- CDR2, and the VHH-CDR3 sequences set forth in SEQ ID NOS.: 24, 25, and 26, respectively. In one instance, the anti-GPC3 VHH comprises or consists of the sequence shown below (Kabat CDR sequences shown in bold): 15 EVQLVESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKEPEWVSSISGG GSSTYYADSLKGRFTISRDNSKNTLYLQMDSLRAEDTAVYYCSRDPRFGEPPFD YWGQGTLVTVSS (SEQ ID NO: 2) In other instances, the anti-GPC3 VHH comprises or consists of a sequence that is at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 20 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to the amino acid sequence of SEQ ID NO:2, wherein the anti-GPC3 VHH comprises a VHH-CDR1, a VHH-CDR2, and a VHH-CDR3 of SEQ ID NO:2. The VHH-CDRs of SEQ ID NO:2 can be based on any CDR definition of the art such as Kabat, Chothia, enhanced Chothia, Aho, Contact, or IMGT. 25 In some instances, the anti-GPC3 VHH comprises or consists of the amino acid sequence of SEQ ID NO:2 except for 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions (e.g., conservative amino acid substitutions) in the framework regions, wherein the anti-GPC3 VHH comprises a VHH-CDR1, a VHH-CDR2, and a VHH- CDR3 of SEQ ID NO:2. The VHH-CDRs of SEQ ID NO:2 can be based on any CDR 30 definition of the art such as Kabat, Chothia, enhanced Chothia, Aho, Contact, or IMGT. 26 Attorney Docket No.: 45817-0177WO1 / MTX980.20 In one instance, the anti-GPC3 VHH comprises or consists of the sequence shown below (Kabat CDR sequences shown in bold): QVQLVESGGGLVQPGGSLRLSCAASGFTFSSYAMSWVRQAPGKEPEWVSSISGG GSSTYYADSLKGRFTISRDNSKNTLYLQMNSLRAEDTAVYYCSRDPRFGEPPFD 5 YWGQGTLVTVSS (SEQ ID NO:150) In other instances, the anti-GPC3 VHH comprises or consists of a sequence that is at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% identical to the amino acid sequence of SEQ ID NO:150, wherein the anti-GPC3 VHH 10 comprises a VHH-CDR1, a VHH-CDR2, and a VHH-CDR3 of SEQ ID NO:150. The VHH-CDRs of SEQ ID NO:150 can be based on any CDR definition of the art such as Kabat, Chothia, enhanced Chothia, Aho, Contact, or IMGT. In some instances, the anti-GPC3 VHH comprises or consists of the amino acid sequence of SEQ ID NO:150 except for 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid 15 substitutions (e.g., conservative amino acid substitutions) in the framework regions, wherein the anti-GPC3 VHH comprises a VHH-CDR1, a VHH-CDR2, and a VHH- CDR3 of SEQ ID NO:150. The VHH-CDRs of SEQ ID NO:150 can be based on any CDR definition of the art such as Kabat, Chothia, enhanced Chothia, Aho, Contact, or IMGT. 20 In one instance, the anti-GPC3 VHH comprises or consists of the sequence shown below (Kabat CDR sequences shown in bold): EVQLVESGGGVVQPGRSLRLSCAASGFTFSNYLMQWVRQAPGKGLVWLSNINS DGSSTDYADSVKGRFTISRDNAKNTLYLQMNSLRAEDTAVYYCRVGAFDYWG QGTLVTVSS (SEQ ID NO:151) 25 In certain instances, the anti-GPC3 VHH comprises a VHH-CDR1, a VHH- CDR2, and a VHH-CDR3 of SEQ ID NO:151. The VHH-CDRs of SEQ ID NO:151 can be based on any CDR definition of the art such as Kabat, Chothia, enhanced Chothia, Aho, Contact, or IMGT. See, e.g., Table 2B. 27

⁰ ₂ ^. ₀ ^{n 8 n} _i i ⁿ _i ^{n n} i₉ X ^h _t ^h _t ^{r h} i t ^{h h} t _t ^rT ^{r M} _{o o /} ^{f f} _t ^r _o ^r _{o o} ^f _{t 1 t} ^{e f} _t ^f _t ^eO ^W ₇ ⁷ ₁ ⁰-⁷ ₁ ⁸ ₅ ⁴ _: ^. _o ^N _t ^e _k ^c _o ^{D y} _e ⁿ _r ^ot _t A ) D 1 _{) 6} T 2 ^{S 2} _{6 )} ³ R D D R R D D : _S G ² O ^D _{: 6} ^{2 C C}- ^C D O _: O - ^{C C}- t_c Q ^N _S H H - H - H H N ^N D ^N H H H V H H V a_t MD n L ^I _I D ^I FD ^I V V V Q ^N _SQ AQ _{e e} ^h _{e e e} ^h H _o Y NE^S LE G S VE^{S h} t _t ^h H C S ₍ W ₍ R ₍ ^{, ,} 1 ₁ t^{, h} _{t t} , ^, ₁ R R ₁ R ₁ R V 3 ₎ ⁹ ₎ ⁰ ₎ ⁶ D D R D D D ⁸ ₂ C Q₅ P M² _: D₆ ² ₅ ^{C C}- ^{C C C}- O T_: ² _{: -} H _{- -} H G- d L i_t ^e _c ^a _i Y N ^N SO O S G ^{N N} H H H H H H V H H V n ⁿ D a _a h h ^{t S} o _F ^{I D}D TQ _S ^I YD D ^I V E ^NQE _FQ _{e e} h ^h V V _e t _e ^h _e ^{h h} t r_e n h F E C G^S _{( I} N^S ₍ AE G^S ₍ t s ^s _e t s t s ^s _e h^t _{e o} ^s _i ^s _i ^r _e ^s _{i e} ^{s s} _i ^{r n r} a _{r : p p} ^r _i ^r _p m ^. _y ^m _o ^. _{p p y} ^{m .} _y ^{m .} _y ^m _o ^{. o} O f _s ^a Y i N ^N _o ^{c l} _e ^{c l} D₎ n h ⁷ _SSD YD₎ ⁶ H ^v _o ^l _o ^{l c} _y ^l i^t H _e H ^v _i ^c _e t H ^v _i ^c _e t H _e H ^v _i ^{t v} _i ^{t o} _i ^{t S t} _{o F} ^I ₅ ² G ^{I D I} ₅ ² H _{c i} h TQ FE_: ^DQE⁾ _{8 F}QE_: V ^e _p V _{c 3} ^e _p H _c V ^e _p H _c H V _c V ^e _{p 3} ^e _p n_i C G^S ₍ O N _S N^S ₍ ⁵ ₂ A G^S ₍ O N ₃ ^s _e C ^s _{e 3} ^s _{e 3} ^s _e C ^s _e f C ^r P ^{r r r} P ^r e P _, G _, CP _, CP _, G _, D G ⁶ K ^G _{- 5} ^{2 -} _i ^{6 t} ₅ ^{6 2 G} _{- 5} ^{3 2} G- ₆ -_i ^{6 t} ₆ V ⁱ _t ^d _n ^{d i} _t ^d _i ^{t 2 d} _n ² R D _S ^{n C} _{a n} ^a _n ⁿ _{a n n n} ^{a d} _n y ₎ D r ⁴ A _{) 5} ⁵ _{) e} ^a _, ^e _h ^{t a} _{, e} ^a _, ^{a e a} _, ^e _h ^{t a} _, a_l ² Y ^{6 h} : D _{5 5} t T ² _: ² _: ^{, 5} s _{5 ,} ^{s 8} ₅ ^h t^{, 0} _{6 h} ^{t 2} _{6 ,} ^{s 5} ₆ p O N S O O S ^{N N e} _s ^2, _e ^{s 2,} _s ^{e 2,} _, ^{s 2,} _e ^{s 2, a} ₄ ⁵ _a ^c ₇ ⁵ _s ^a _{9 e} 5 ^s _{a 1} ⁶ _a ^c ₄ m QD G D D _{c 2} ⁿ _{2 c} ^{c r 6 e t I D I} Y ^I _{e i e 2} ^r _{2 e 2 x a} E ^b M a LQ _S Q ^D YE ^N E _FQE ^m :_.S ^a _t ^r :_.S ^m :_.S _e : h _. ^h _t :_. K N ₍ N ₍ G ₍ ^s _t S ^r S - ^S _I ^S A^S _o O _e N ^c O _o N ^s O N ^o O _u ^f O B ^{2 n} _I ^{n n n N n N} D _{I I I I} e_l - b H H₁ - R H₂ - R H₃ R ^I D ^I D ^I D ^I D ^I a H HD HD HD Q Q Q Q Q T V V C V C V C E S E S E S E S E S 5 ⁰ ₁ Attorney Docket No.: 45817-0177WO1 / MTX980.20 In other instances, the anti-GPC3 VHH comprises or consists of a sequence that is at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, or at least 99% 5 identical to the amino acid sequence of SEQ ID NO:151, wherein the anti-GPC3 VHH comprises a VHH-CDR1, a VHH-CDR2, and a VHH-CDR3 of SEQ ID NO:151. The VHH-CDRs of SEQ ID NO:151 can be based on any CDR definition of the art such as Kabat, Chothia, enhanced Chothia, Aho, Contact, or IMGT. In some instances, the anti-GPC3 VHH comprises or consists of the amino acid 10 sequence of SEQ ID NO:151 except for 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions (e.g., conservative amino acid substitutions) in the framework regions, wherein the anti-GPC3 VHH comprises a VHH-CDR1, a VHH-CDR2, and a VHH- CDR3 of SEQ ID NO:151. The VHH-CDRs of SEQ ID NO:151 can be based on any CDR definition of the art such as Kabat, Chothia, enhanced Chothia, Aho, Contact, or 15 IMGT. Chimeric Antigen Receptors In some aspects, the present disclosure provides a chimeric antigen receptor (CAR) comprising any anti-GPC3 VHH described above. 20 In some instances, CARs of the present disclosure comprise an antigen binding domain (e.g., anti-GPC3 VHH), a hinge domain, a transmembrane domain, and an intracellular signaling domain. In some instances, the CARs comprise an antigen binding domain, a spacer domain, a transmembrane domain, a costimulatory domain, and a signaling domain. 25 In some aspects, the antigen binding domain (e.g., anti-GPC3 VHH) may be operably linked to another domain of the CAR, such as the hinge domain, the transmembrane domain and/or the intracellular domain, both described elsewhere herein, for expression in an immune cells (e.g., a T cell, a macrophage). In some aspects, a first nucleic acid sequence encoding the antigen binding domain (e.g., anti-GPC3 VHH) is 30 operably linked to a second nucleic acid encoding a hinge and transmembrane domain, 29 Attorney Docket No.: 45817-0177WO1 / MTX980.20 and further operably linked to a third a nucleic acid sequence encoding an intracellular domain. In some cases, the nucleic acid is mRNA. In some aspects, the antigen binding domains described herein (e.g., anti-GPC3 VHH) can be combined with any of the transmembrane domains described herein, any 5 of the intracellular domains or cytoplasmic domains described herein, or any of the other domains described herein that may be included in a CAR of the present disclosure. In some aspects, the CAR may also include a spacer domain as described herein. In some aspects, each of the antigen binding domain, transmembrane domain, and intracellular domain is separated by a linker. 10 Antigen Binding Domain The antigen binding domain of a CAR is an extracellular region of the CAR for binding to a specific target antigen including proteins, carbohydrates, and glycolipids. In 15 some aspects, the CAR comprises affinity to a target antigen (e.g., GPC3) on a target cell. The target antigen may include any type of protein, or epitope thereof, associated with the target cell. For example, the CAR may comprise affinity to a target antigen on a target cell that indicates a particular disease state of the target cell. In some aspects, the target cell antigen is or comprises a GPC3 expressed on the 20 cell surface. In some aspects, the CAR has affinity and/or specificity for GPC3, a GPC3 epitope, a GPC3 mutant, and/or a GPC3 fragment. As described herein, a CAR of the present disclosure having affinity for a specific target antigen (e.g., GPC3) on a target cell may comprise a target-specific binding domain. In some instances, the target-specific binding domain is obtained from HCAb 25 mice. In some instances, the target-specific binding domain is a llama target-specific binding domain, e.g., the target-specific binding domain is of llama origin. In some instances, the target-specific binding domain is a human target-specific binding domain, e.g., the target-specific binding domain is a humanized form of a llama VHH. 30 Attorney Docket No.: 45817-0177WO1 / MTX980.20 In some instances, the antigen binding domain of a CAR comprises or consists of an anti-GPC3 described above in the section entitled Anti-GPC3 Binding Polypeptides. In some instances, anti-GPC3 VHHs have single digit nM range affinity for human GPC3. 5 For example, in some instances, the antigen binding domain of the CAR comprises a VHH-CDR1, a VHH-CDR2, and a VHH-CDR3 of SEQ ID NO:2 or SEQ ID NO:150. In certain cases, the VHH-CDR1, the VHH-CDR2, and the VHH-CDR3 of SEQ ID NO:2 or SEQ ID NO:150 are sequences based on any one of the CDR definitions shown in Table 2A. In other instances, the antigen binding domain of the CAR comprises 10 a VHH-CDR1, a VHH-CDR2, and a VHH-CDR3 of SEQ ID NO:151. In certain cases, the VHH-CDR1, the VHH-CDR2, and the VHH-CDR3 of SEQ ID NO:151 are sequences based on any one of the CDR definitions shown in Table 2B. In other instances, the antigen binding domain of the CAR contains a VHH domain having an amino acid sequence that is at least 85% identical (e.g., at least 85%, 15 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% identical) to the amino acid sequence of SEQ ID NO:2, 150, or 151, wherein there are no changes made to the VHH-CDRs. In some cases, the antigen binding domain of the CAR contains a VHH domain having an amino acid sequence that is at least 90% identical (e.g., at least 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100% 20 identical) to the amino acid sequence of SEQ ID NO:2, 150, or 151, wherein there are no changes made to the VHH-CDRs. In certain cases, the antigen binding domain of the CAR contains a VHH domain having an amino acid sequence that is at least 95% identical (e.g., at least 95%, 96%, 97%, 98%, 99%, or 100% identical) to the amino acid sequence of SEQ ID NO:2, 150, or 151, wherein there are no changes made to the VHH- 25 CDRs. In some cases, the antigen binding domain of the CAR contains an anti-GPC3 VHH domain having an amino acid sequence that comprises or consists of the amino acid sequence of SEQ ID NO:2, 150, or 151 except for 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid substitutions (e.g., conservative amino acid substitutions) in the framework regions, wherein the anti-GPC3 VHH comprises a VHH-CDR1, a VHH-CDR2, and a VHH- 31 Attorney Docket No.: 45817-0177WO1 / MTX980.20 CDR3 of SEQ ID NO:2. The VHH-CDRs of SEQ ID NO:2, 150, or 151 can be based on any CDR definition of the art such as Kabat, Chothia, enhanced Chothia, Aho, Contact, or IMGT. In some cases, the antigen binding domain of the CAR contains a VHH domain comprising or consisting of the amino acid sequence of SEQ ID NO:2. In other cases, the 5 antigen binding domain of the CAR contains a VHH domain comprising or consisting of the amino acid sequence of SEQ ID NO:150. In yet other cases, the antigen binding domain of the CAR contains a VHH domain comprising or consisting of the amino acid sequence of SEQ ID NO:151. 10 Spacer Domain In some aspects, the anti-GPC3 CAR comprises a spacer domain. In some aspects, the spacer domain is an oligopeptide or polypeptide that functions to link one or more of the antigen binding domain, transmembrane domain, costimulatory domain, and signaling domain to one or more of the antigen binding domain, transmembrane domain, 15 costimulatory domain, and signaling domain. In some aspects, the spacer domain may be a short amino acid linker comprising 2, 3, 4, 5, 6, 7, 8, 9 or 10 amino acids in length. For example, a glycine-serine doublet. In some aspects, the spacer domain occurs between the intracellular domain and the transmembrane domain of the CAR. In some aspects, the spacer domain occurs between the extracellular domain and the transmembrane domain. 20 In some aspects, the spacer domain may comprise up to 300 amino acids, e.g., 10 to 100 amino acids, or 25 to 50 amino acids. Non-limiting examples of linkers are disclosed in WO 2015/105522. In some aspects, the spacer domain comprises an immunoglobulin Fc domain. In some aspects, the spacer domain comprises an IgG Fc domain. In some aspects, the 25 spacer domain comprises an IgG4 Fc domain. In some aspects, the IgG4 Fc domain comprises one of the following: ESKYGPPCPPCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQE DPEVQFNWYVDGVEVHNAKTKPREEQFQSTYRVVSVLTVLHQDWLNGKEYKC KVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLTCLVKGFYPSDI 32 Attorney Docket No.: 45817-0177WO1 / MTX980.20 AVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSVMHE ALHNHYTQKSLSLSLGK (SEQ ID NO: 268); ESKYGPPCPPCPGGGSSGGGSGGQPREPQVYTLPPSQEEMTKNQVSLTCL VKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNV 5 FSCSVMHEALHNHYTQKSLSLSLGK (SEQ ID NO: 269); ESKYGPPCPSCPAPEFEGGPSVFLFPPKPKDTLMISRTPEVTCVVVDVSQE DPEVQFNWYVDGVEVHQAKTKPREEQFNSTYRVVSVLTVLHQDWLNGKEYKC KVSNKGLPSSIEKTISKAKGQPREPQVYTLPPSQEEMTKNQVSLTCLVKGFYPSDI AVEWESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSVMHE 10 ALHNHYTQKSLSLSLGK (SEQ ID NO: 270); PKDTLMISRTPEVTCVVVDVSQEDPEVQFNWYVDGVEVHQAKTKPREEQ FNSTYRVVSVLTVLHQDWLNGKEYKCKVSNKGLPSSIEKTISKAKGQPREPQVY TLPPSQEEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENNYKTTPPVLDSDGSF FLYSRLTVDKSRWQEGNVFSCSV MHEALHNHYTQKSLSLSLGK (SEQ ID NO: 15 271); or GQPREPQVYTLPPSQEEMTKNQVSLTCLVKGFYPSDIAVEWESNGQPENN YKTTPPVLDSDGSFFLYSRLTVDKSRWQEGNVFSCSVMHEALHNHYTQKSLSLS LGK (SEQ ID NO: 272). In some aspects, tolerable variations in the IgG4 Fc domain will be known to 20 those of skill in the art. In some aspects, the IgG4 Fc domain comprises an amino acid sequence that has at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 86%, at least about 87%, at least about 88%, at least about 89%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, 25 at least about 97%, at least about 98%, or at least about 99% sequence identity to any one of SEQ ID NOs: 268-272. Hinge Domain 33 Attorney Docket No.: 45817-0177WO1 / MTX980.20 In some aspects, the anti-GPC3 CAR comprises a hinge domain. The hinge domain of the CAR is a hydrophilic region that can be located between the antigen binding domain and the transmembrane domain. In some aspects, this domain may facilitate proper protein folding for the CAR, among other functions. The hinge domain is 5 an optional component for the CAR. In some aspects, the transmembrane domain further comprises a hinge domain. The hinge domain may include a domain selected from Fc fragments of antibodies, hinge regions of antibodies, CH2 regions of antibodies, CH3 regions of antibodies, artificial hinge sequences or combinations thereof. Examples of hinge domains include, without limitation, a CD8a hinge, a CD28 hinge, artificial hinges 10 made of polypeptides which may be as small as, three glycines (Gly), as well as CH1 and CH3 domains of IgGs (such as human IgG4). In some aspects, the CAR includes a hinge domain that connects the antigen binding domain with the transmembrane domain, which, in turn, connects to the intracellular domain. The hinge domain is preferably capable of supporting the antigen 15 binding domain to recognize and bind to the target antigen on the target cells. In some aspects, the hinge domain is a flexible domain, thus allowing the antigen binding domain to have a structure to optimally recognize the specific structure and density of the target antigens on a cell such as tumor cell. The flexibility of the hinge domain permits the hinge region to adopt many different conformations. 20 In some cases, the hinge domain is an immunoglobulin heavy chain hinge region. In some cases, the hinge domain is a polypeptide derived from a receptor (e.g., a CD8 hinge region or a CD28 hinge region). In some aspects, the hinge domain can have a length of from about 4 amino acids to about 50 amino acids, e.g., from about 4 aa to about 10 aa, from about 10 aa to about 25 15 aa, from about 15 aa to about 20 aa, from about 20 aa to about 25 aa, from about 25 aa to about 30 aa, from about 30 aa to about 40 aa, or from about 40 aa to about 50 aa. In some aspects, the hinge domain can be of any of a number of suitable lengths, such as from 1 amino acid (e.g., Gly) to 20 amino acids, from 2 amino acids to 15 amino acids, from 3 amino acids to 12 amino acids, including 4 amino acids to 10 amino acids, 34 Attorney Docket No.: 45817-0177WO1 / MTX980.20 5 amino acids to 9 amino acids, 6 amino acids to 8 amino acids, or 7 amino acids to 8 amino acids, and can be 1, 2, 3, 4, 5, 6, or 7 amino acids. For example, in some embodiments, a linker or hinge may comprise an IgG4 hinge or derivative thereof, an IgG2 hinge or derivative thereof, a CD28 hinge, or a CD8 5 hinge. Specific examples of linker and hinge domains are included in Table 3 below, but are not intended to be limiting. Table 3 – Examples of Linker and Hinge Domain Sequences SEQ ID Description Sequence NO F T D 35 Attorney Docket No.: 45817-0177WO1 / MTX980.20 31 IgG4-2 GQPREPQVYTLPPSQEEMTKNQVSLTCLVKGFYPSDIAVE WESNGQPENNYKTTPPVLDSDGSFFLYSRLTVDKSRWQEG In some aspects, the anti-GPC3 CARs of the present disclosure may comprise a transmembrane domain that connects the antigen binding domain of the CAR to the 5 intracellular domain of the CAR. In some cases, the anti-GPC3 CARs of the present disclosure comprise a hinge domain and a transmembrane domain that connects the antigen binding domain of the CAR to the intracellular domain of the CAR. The transmembrane domain of a subject CAR is a region that is capable of spanning the plasma membrane of a T cell . The transmembrane domain is for insertion into a cell 10 membrane, e.g., a eukaryotic cell membrane. In some aspects, the transmembrane domain is interposed between the antigen binding domain and the intracellular domain of a CAR. In some aspects, the transmembrane domain is naturally associated with one or more of the domains in the CAR. In some aspects, the transmembrane domain can be selected or modified by one or more amino acid substitutions to avoid binding of such 15 domains to the transmembrane domains of the same or different surface membrane proteins, to minimize interactions with other members of the receptor complex. The transmembrane domain may be derived either from a natural or a synthetic source. Where the source is natural, the domain may be derived from any membrane- bound or transmembrane protein, e.g., a Type I transmembrane protein. Where the source is 20 synthetic, the transmembrane domain may be any artificial sequence that facilitates insertion of the CAR into a cell membrane, e.g., an artificial hydrophobic sequence. In some aspects, the transmembrane domain is a transmembrane domains derived from (i.e. comprise at least the transmembrane region(s) of) the alpha, beta or zeta chain of the T cell receptor, CD28, CD3 epsilon, CD45, CD4, CD5, CD7, CD8, CD9, CD16, CD22, 25 CD33, CD37, CD64, CD80, CD86, CD134 (OX-40), CD137 (4-1BB), CD154 (CD40L), Toll-like receptor 1 (TLR1), TLR2, TLR3, TLR4, TLR5, TLR6, TLR7, TLR8, and 36 Attorney Docket No.: 45817-0177WO1 / MTX980.20 TLR9. In some aspects, the transmembrane domain may be synthetic, in which case it will comprise predominantly hydrophobic residues such as leucine and valine. Preferably a triplet of phenylalanine, tryptophan and valine will be found at each end of a synthetic transmembrane domain. 5 In some aspects, tolerable variations in the transmembrane domain will be known to those of skill in the art. Specific examples of transmembrane domains are included in Table 4 below, but are not intended to be limiting. Table 4 – Examples of Transmembrane Domain Sequences SEQ ID Description Sequence NO V P H 1 Costimulatory Domain In some aspects, costimulatory signals are necessary to achieve robust CAR functionality (e.g., expansion, function, persistence, and anti-tumor activity). These can 37 Attorney Docket No.: 45817-0177WO1 / MTX980.20 be provided by incorporating one or more costimulatory domains from one or more costimulatory molecules (e.g., T cell costimulatory molecules). In some aspects, costimulatory domains are selected from the costimulatory molecules of CD3, CD4, CD8, T cell receptor (TCR), CD27, CD28, 4-1BB (CD137), 0X40, CD30, CD40, PD-l, 5 ICOS, lymphocyte function-associated antigen-l (LFA-l), CD2, CD7, LIGHT, NKG2C, B7-H3, or any fragment thereof. In some aspects, the costimulatory domain comprises a 4-1BB costimulatory domain. In some aspects, the 4-1BB costimulatory domain comprises KRGRKKLLYIFKQPFMRPVQTTQEEDGCSCRFPEEEEGGCEL (SEQ ID NO: 42). 10 In some aspects, the costimulatory domain comprises a CD28 costimulatory domain. In some aspects, the CD28 costimulatory domain comprises RSKRSRLLHSDYMNMTPRRPGPTRKHQYPYAPPRDFAAYRS (SEQ ID NO: 43). In some aspects, the costimulatory domain comprises an OX40 costimulatory domain. In some aspects, the OX40 costimulatory domain comprises 15 ALYLLRRDQRLPPDAHKPPGGGSFRTPIQEEQADAHSTLAKI (SEQ ID NO: 44). In some aspects, tolerable variations in the costimulatory domain will be known to those of skill in the art. In some aspects, the costimulatory domain comprises an amino acid sequence that has at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 86%, at least about 87%, 20 at least about 88%, at least about 89%, at least about 90%, at least about 91%, at least about 92%, at least about 93%, at least about 94%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, or at least about 99% sequence identity to SEQ ID NO: 42, SEQ ID NO:43, or SEQ ID NO: 44. 25 Intracellular Signaling Domain In some aspects, the anti-GPC3 VHH CAR also includes an intracellular signaling domain. The terms “intracellular signaling domain” and “intracellular domain” are used interchangeably herein. The intracellular signaling domain of the CAR is responsible for activation of at least one of the effector functions of the T cell in which the CAR is 38 Attorney Docket No.: 45817-0177WO1 / MTX980.20 expressed . The intracellular signaling domain transduces the effector function signal and directs the T cell to perform its specialized function, e.g., harming and/or destroying a target cell. In some aspects, the intracellular signaling domain is the cytoplasmic portion of a 5 surface receptor, co-stimulatory molecule, or any molecule that acts in concert to initiate signal transduction in a T cell, as well as any derivative or variant of these elements and any synthetic sequence that has the same functional capability. In some aspects, the intracellular signaling domain is the z chain of the T cell receptor complex or any of its homologs, e.g., h chain, FcsRfy and b chains, MB 1 (IgA) 10 chain, B29 (Ig) chain, etc., human CD3 ζ chain, CD3 polypeptides (A, d and e), syk family tyrosine kinases (Syk, ZAP 70, etc.), src family tyrosine kinases (Lck, Fyn, Lyn, etc.), and other molecules involved in T cell transduction, such as CD2, CD5 and CD28. In some aspects, the intracellular signaling domain may be human CD3ζ chain, FcyRIII, FcsRI, cytoplasmic tails of Fc receptors, an immunoreceptor tyrosine-based activation 15 motif (ITAM) bearing cytoplasmic receptors, and combinations thereof. In some cases, the intracellular signaling domain is from the human CD3ζ chain with 3 ITAMs (e.g., SEQ ID NO: 45). In one case, the intracellular signaling domain is from FCεR1γ (1 ITAM) (e.g., SEQ ID NO: 4). In some cases, the FCεR1γ ITAM consists of the sequence: DGVYTGLSTRNQETYETL (SEQ ID NO: 116) In another case, the intracellular 20 signaling domain is from FCεR1γ (1 ITAM) (e.g., SEQ ID NO: 4) and further comprises Myd88 and CD40 domains. In some aspects the intracellular signaling domain includes a fragment or domain from one or more molecules or receptors including, but not limited to, TCR, CD3 zeta, CD3 gamma, CD3 delta, CD3 epsilon, CD86, common FcR gamma, FcR beta (Fc 25 Epsilon Rib), CD79a, CD79b, Fcgamma Rlla, DAP 10, DAP 12, T cell receptor (TCR), CD8, CD27, CD28, 4-1BB (CD137), OX9, 0X40, CD30, CD40, PD-l, ICOS, a KIR family protein, lymphocyte function-associated antigen-l (LFA-l), CD2, CD7, LIGHT, NKG2C, B7-H3, a ligand that specifically binds with CD83, CDS, ICAM-l, GITR, BAFFR, HVEM (LIGHTR), SLAMF7, NKp80 (KLRF1), CD127, CD 160, CD19, CD4, 39 Attorney Docket No.: 45817-0177WO1 / MTX980.20 CD8alpha, CD8beta, IL2R beta, IL2R gamma, IL7R alpha, ITGA4, VLA1, CD49a, ITGA4, IA4, CD49D, ITGA6, VLA-6, CD49f, ITGAD, CD1 Id, ITGAE, CD 103, ITGAL, CD 11 a, LFA-l, ITGAM, CD lib, ITGAX, CD l lc, ITGB1, CD29, ITGB2, CD 18, LFA- 1, ITGB7, TNFR2, TRANCE/RANKL, DNAM1 (CD226), SLAMF4 (CD244, 5 2B4), CD84, CD 96 (Tactile), CEACAM1, CRT AM, Ly9 (CD229), CD160 (BY55), PSGL1, CD 100 (SEMA4D), CD69, SLAMF6 (NTB-A, Lyl08), SLAM (SLAMF1, CD150, IPO-3), BLAME (SLAMF8), SELPLG (CD 162), LTBR, LAT, GADS, SLP-76, PAG/Cbp, NKp44, NKp30, NKp46, NKG2D, Toll-like receptor 1 (TLR1), TLR2, TLR3, TLR4, TLR5, TLR6, TLR7, TLR8, TLR9, TLR10, TLR11, TLR12, TLR13, other co- 10 stimulatory molecules described herein, any derivative, variant, or fragment thereof, any synthetic sequence of a co stimulatory molecule that has the same functional capability, and any combination thereof. In some aspects, the intracellular signaling domain is a CD3ζ signaling domain, such as 15 RVKFSRSADAPAYQQGQNQLYNELNLGRREEYDVLDKRRGRDPEMGGKPRRK NPQEGLYNELQKDKMAEAYSEIGMKGERRRGKGHDGLYQGLSTATKDTYDAL HMQALPPR (SEQ ID NO: 45) In some cases, an anti-GPC3 VHH CAR of the present disclosure may comprise the intracellular signaling domain of a TLR, including TLR1, TLR2, TLR3, TLR4, 20 TLR5, TLR6, TLR7, TLR8, TLR9, TLR10, TLR11, TLR12, and TLR13. Switching between the various TLRs can alter the cytokine response of monocytic cells. The signaling domains of TLR4 and TLR9 are particularly useful for treating cancer, but for the purposes of the present disclosure, the chimeric receptor could alternatively comprise the signaling domain of TLR1, TLR2, TLR3, TLR5, TLR6, TLR7, TLR8, TLR10, 25 TLR11, TLR12, or TLR13. Examples of TLR signaling domain amino acid sequences are shown in Table 5. Table 5 – Examples of TLR Signaling Domain Amino Acid Sequences. 40 Attorney Docket No.: 45817-0177WO1 / MTX980.20 SEQ ID Description Sequence NO: K S E C H N or GMCSFRa signal peptide, such as MLLLVTSLLLCELPHPAFLLIP (SEQ ID NO: 48), which is ultimately cleaved off of the mature CAR. In some instances, the CAR 5 temporarily expresses the signal peptide, MALPVTALLLPLALLLHAARP (SEQ ID NO:1). Exemplary Anti-GPC3 VHH CAR In one aspect, the disclosure provides an anti-GPC3 VHH CAR (i.e., a GPC3 10 binding CAR) that comprises a VHH comprising an amino acid sequence that is at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% identical to the amino acid sequence of any one of SEQ ID NO:2, 150, or 151. The C-terminal of the anti-GPC3 VHH is attached to the N-terminal of a CD28 hinge region. In some cases, the 15 CD28 hinge region comprises or consists of a sequence that is at least 80%, at least 85%, 41 Attorney Docket No.: 45817-0177WO1 / MTX980.20 at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% identical to the amino acid sequence of SEQ ID NO: 27. The C-terminal of the hinge region is linked to the N- terminal of a CD28 transmembrane region. In some cases, the CD28 transmembrane 5 region comprises a sequence that is at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% identical to the amino acid sequence of SEQ ID NO:33. In certain cases, the combined CD28 hinge and CD28 transmembrane region comprises a sequence that is at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at 10 least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% identical to the amino acid sequence of SEQ ID NO:3. The C-terminal of the CD28 transmembrane region is linked to the N-terminal of a FCεR1γ/ITAM. In some cases, the FCeR1gamma/ITAM comprises a sequence that is at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 15 96%, at least 97%, at least 98%, at least 99%, or 100% identical to the amino acid sequence of SEQ ID NO:4. In some cases, the anti-GPC3 VHH CAR comprises a signal sequence. In one case, the signal sequence is a CD8L signal sequence. In certain cases, the signal sequence comprises a sequence that is at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 20 97%, at least 98%, at least 99%, or 100% identical to the amino acid sequence of SEQ ID NO: 1. In certain instances, the mature anti-GPC3 VHH CAR comprises a sequence that is at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% 25 identical to the amino acid sequence of SEQ ID NO:5. In some instances, the anti-GPC3 VHH CAR comprises a sequence that is at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% identical to the amino acid sequence of SEQ ID NO:6. 42

⁰ ₂ ^. ₀ ⁸ ₉ XT ^M _{/ 1} O ^W ₇ ⁷ ₁ ⁰-⁷ ₁ ⁸ ₅ ⁴ _: ^. _o ^N _t ^e _k ^c _o ^{D y} _e ⁿ _r ^ot _t A ^G- p i L G P t^{n m} L P T R ^N A E G S H a _o Q S P _S Y Q G C ^I n C AL V S G D K V S V Y _IT a _f R E T ^T L G Y f ^o P L L G G S N V D L _I ^S A G _I G o ^e s^t _c L S V ^N L G G C L L G S A _S G ^S Y Y S A G T K n ^{n e} _eu n^{o q e} A _I P Y K S V E T S S Y P R D N e _c E S V p ^{S n} _e VP V V A P C A V E W V E E A D u L L T Y L ^Q L P L Q W M V _I E R Y m d c ^{i q} A E D V K Q L P o _{c e} V P E G L V K S P y A S M E E A ^E _I G R E G D P r_a ^l _{o p} ⁿ _i ^/ _a ^t m m ⁿ _l ^a _u e_x ^A _o ⁱ _n ^g H m ^{f m} _o ^o _h ^t ₎ E ^– _t 6 ^p _{i e} H M _{a e i i} ^{S c} l ^r _n ^e V ^T _/ ^{g e} ₁ A ^c _n ^e w ^{e ( l} _c ^{n e b} _c ^{s L} _{u 3} ^{8 R} M ^A _{u a e a e 8} D ^q CP _{2 g} D ⁿ D C _{e i e} C A _l T ^l _u ^q R e A ⁿ _g ^{u i} _q ^e T S G C H F _I F S C _{s s}

⁰ ₂ ^. ₀ ² _: ⁿ i ⁸ ₉ O R X ^N AT ^M _{/ 1} O ^W ₇ ⁷ ₁ ⁰-⁷ ₁ ⁸ ₅ ⁴ _: ^. _o ^N _t ^e _k ^c _o ^{D y} _e ⁿ _r ^ot _t ^N _o ^f _a A _{t c} Y C L P ^{P T} D ^{I e i} _{g e} ^{n h s} _{u i} ^d _{e e} ^d _i ^q _e ^s T S S P _{S I s} ^l _c ^d _n ^b _i ^s _{o ,} ^. E L D E P A Q _s ^{e u i r e} Q R A G C A E ^S _{c n b c} ^s _l ^c _g ^. _e ^. N L _n S Y F L K ^{f n} R Y R H R _{o e} ^u _g ⁿ _{3 e i} CP ^d _u ^{n ( s} _e ⁱ _e ^r T G T P K V _{e q} ^s _s R ^d S G S D G ^{Q n e} _s ^e _r G A _e ^{d k} _i ^t _e ^h L P S R K _{I o e} ^p _a C _n G ⁱ _o ^{e d} Q G S V K _e T V C H L ^s _i ^{h r} _{t x} ^e _e ^d _{a l l o o} ^{f c} _{e u} ^b _i ^r Y L G Y ^I _I R _{p e} ^{s y c v} _{i o)} ⁿ _c V G G G G ^S T V I Y m _i G W ^{o r} _{b p d n} e ^{et v n} F _y R ^{l s} o _e ^d D G S V S A ^N _S F^I _I Q _{c s} ^m _{o s} ^s _a ^h i t ^{e O} ₍ ^{p s e} _d ⁴ ₄ S S T K F PP R ^c _e ^r _{d e e} ⁱ _t K E V E D E V W A K A ^o _{p s} ^o _c ^d _i ^p _e Y E N V ^C _s ^{l x} A ^{n m} S L E E _a ^{v p} A D T _{a e} N _e ^r _{f o} ^r _y ^{l T} _I Q P H V E R L V H _{s e} Y L K H R ^b R _d n m ⁿ _{a g p} n _e ^r _o ^p A E K LS P ^L L V A _{a s ) i} P G P _SY T ₃ ^{C c )} _s ^{a n d} _{a u} ^s R A P D P E C H ⁿ F ^h _a ^e _{r o} ^l A K R A M Y C Y P _i ^e R _c ^u m _c ^s C R A Q M A T ^G H _r ^e _s ^u _n ^e _{i g} V A Q L E -ⁱ V Q _h O ⁽ _{s h p} ^{d n} _{i I} H R L V L V Y ^E V I G Q _t N ⁿ _{3 d} ^s _e ^e _d , K L L S ⁱ _. ^{g o e} _h ^{t d} _n L L W T S G _a ^C V R _y R ^r _P ^e _b ⁱ _{t . r} m ^o _e ^e ₍ ⁿ _{a ,} ^{r i} _b V A S N V V TS _a L M K T V L ^{l G}- _p ⁱ _t ^c W ⁿ _s ^{a e} _r ^l F _{c s} u ^t _{g a c} ^{n e} _i ^{l s} _{u 3} c CP P A S V L G m _{a d g n j i} ^r _i ^t F ^{G I} _I Q LL Y N L V W T ^e _{x y} ^r _s R ⁿ _i ^y _l ^{b o} _u ^s _{p r} m ^a _p ^a F PP L SS D T A R G F Y V ^er _a ^l d p A ^a _{e p s} ^o _{t o} ^c _n ^{I g} _n V K A F T E T V T ^S _I Q P K G _e ^{C e} F T G _S D ^h _t ^o m^{e R} _r ^u _d ^e _, A _. ^{i n} _d ^o V H P F P S ^, _{s x} H e H ⁿ _{e t} ^a _r ^e _{i t} N ^e _{r c} ⁿ L K L_S L L GS R W Y G K P E ^e _c ^r _e V ^. p _{e )} ^{O f s} _i R m ^e _{h e s} Y T A A G E M A K D F F L Y S ⁿ _a ^{h t} _{t 3 s} ^o C ⁿ _a d ^e _r ^{n u} _i , m _{. d} ^{e e} _d ^{i n} P n _s ^g _{. b t} i ^e _s G ^m _u ^{a o} _l ^d _a ^{e i} _r ^o _e f ^r _e ^e _h -_i ^t o _n ^h _, ^s h ^h _t ^{T .} _e ^c d . ^a _g ^{. i} _{s t} ⁱ _e ^, _s ^c _s ^l d ^{b e} s ⁿ _{a d} ^{i e} _{c t d} ^u _{n e} ^t _{i )} ^o ₎ ^e _e ^{( o i c o} _e ^d _g A ^{c A} _n w ^{e (} l ^{e l} _c ^{n n} _I ^{6 e} _h T _{t e} c ^l _{c h} T ⁾ _{s e} ^l _{c i} ^t _p ⁿ _i ^{s l} _{u u} ^q R _{a e l} ^b _e ^j u A ^{u e} _i ^r A ^{n u} _{q a b} ⁿ _y N _n ^y _p ^y _p F _e S C _g ⁱ _s ^e _s ^{T u n} _{i s} ^l a _o R _{l l} m P m ^o _p ^o _p ^o _{c 5} ⁰ ₁ Attorney Docket No.: 45817-0177WO1 / MTX980.20 In some instances, the polynucleotide (e.g., a RNA, e.g., an mRNA) of the disclosure comprises a nucleotide sequence (e.g., an ORF) that encodes a GPC3 binding CAR polypeptide described herein. In certain cases, the nucleotide sequence encodes a polypeptide that comprises a sequence that is at least 90%, at least 91%, at least 92%, at 5 least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% identical to any one of SEQ ID NOs: 5 or 6. In some cases, the polynucleotide (e.g., a RNA, e.g., an mRNA) of the disclosure comprises a nucleotide sequence (e.g., an ORF) that encodes a GPC3 binding CAR polypeptide described herein of any one of SEQ ID NOs: 5 or 6 with 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 amino acid10 substitutions. In certain instances, the substitutions are in regions that are not the VHH- CDR1, VHH-CDR2, or VHH-CDR3 of the anti-GPC3 VHH of the CAR. In some cases, the polynucleotide (e.g., a RNA, e.g., an mRNA) of the disclosure comprises a sequence that is at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% 15 identical to SEQ ID NO: 8. In other cases, the polynucleotide (e.g., a RNA, e.g., an mRNA) of the disclosure comprises a sequence that is at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% sequence identical to SEQ ID NO:9. In certain cases, the polynucleotide comprises a sequence of SEQ ID NO: 8 or 9 with 1, 2, 3, 4, 5, 6, 7, 8, 9, 20 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 nucleic acid substitutions. In certain instances, the substitutions are in regions that do not code for the VHH-CDR1, VHH-CDR2, or VHH-CDR3 of the encoded anti-GPC3 VHH of the CAR. In some instances, the polynucleotide of the disclosure (e.g., an RNA, e.g., an mRNA) comprises a nucleotide sequence (e.g., an ORF, e.g., SEQ ID NO:8 or 9) 25 encoding a GPC3 binding CAR polypeptide described herein further comprises a 5′-UTR (e.g., SEQ ID NO:7) and a 3′-UTR (e.g., SEQ ID NO:10). In certain cases, the polynucleotide (e.g., a RNA, e.g., an mRNA) comprises a 5′ terminal cap (e.g., m⁷Gp- ppGm-A, Cap0, Cap1, ARCA, inosine, N1-methyl-guanosine, 2′-fluoro-guanosine, 7- deaza-guanosine, 8-oxo-guanosine, 2-amino-guanosine, LNA-guanosine, 2- 30 azidoguanosine, Cap2, Cap4, 5′ methylG cap, or an analog thereof) and a poly A-tail 45 Attorney Docket No.: 45817-0177WO1 / MTX980.20 region (e.g., about 100 nucleotides in length (SEQ ID NO: 117)). In some cases, the mRNA comprises a poly A tail. In some cases, the poly A tail comprises the sequence of SEQ ID NO:117. In some instances, the poly A tail is protected (e.g., with an inverted deoxy-thymidine). In some instances, the poly A tail comprises A100-UCUAG-A20- 5 inverted deoxy-thymidine (SEQ ID NO:13). In some instances, the poly A tail is A100- UCUAG-A20-inverted deoxy-thymidine (SEQ ID NO:13). In some instances, the polynucleotide (e.g., a RNA, e.g., an mRNA) comprises a nucleotide sequence (e.g., an ORF) encoding a GPC3 binding CAR polypeptide of this disclosure is single stranded or double stranded. 10 In some instances, the polynucleotide comprising a nucleotide sequence (e.g., an ORF) encoding GPC3 binding CAR polypeptide described herein is DNA or RNA. In some cases, the polynucleotide of the disclosure is RNA. In some cases, the polynucleotide of the disclosure is, or functions as, an mRNA. In some cases, the mRNA comprises a nucleotide sequence (e.g., an ORF) that encodes a GPC3 binding CAR 15 polypeptide described herein, and is capable of being translated to produce the GPC3 binding CAR protein described herein in vitro, in vivo, in situ or ex vivo. In some cases, the polynucleotide of the disclosure (e.g., a RNA, e.g., an mRNA) comprises a sequence-optimized nucleotide sequence (e.g., an ORF) encoding a GPC3 binding CAR protein described herein, wherein the polynucleotide comprises at least one 20 chemically modified nucleobase, e.g., N1-methylpseudouracil or 5-methoxyuracil. In certain cases, all uracils in the polynucleotide are N1-methylpseudouracils. In other cases, all uracils in the polynucleotide are 5-methoxyuracils. In some cases, the polynucleotide further comprises a miRNA binding site, e.g., a miRNA binding site that binds to miR-142 and/or a miRNA binding site that binds to miR-126 and/or a miRNA 25 binding site that binds to miR-122. In some cases, the polynucleotide (e.g., a RNA, e.g., an mRNA) disclosed herein is formulated with a delivery agent. In some cases, the delivery agent comprises an ionizable amino lipid, a helper lipid, a sterol (e.g., Cholesterol), and a PEG lipid (e.g., PEG-DMG), e.g., with a mole ratio in the range of about (i) 40-50 mol% ionizable amino 46 Attorney Docket No.: 45817-0177WO1 / MTX980.20 lipid, optionally 45-50 mol% ionizable amino lipid, for example, 45-46 mol%, 46-47 mol%, 47-48 mol%, 48-49 mol%, or 49-50 mol% for example about 45 mol%, 45.5 mol%, 46 mol%, 46.5 mol%, 47 mol%, 47.5 mol%, 48 mol%, 48.5 mol%, 49 mol%, or 49.5 mol%; (ii) 30-45 mol% sterol (e.g., cholesterol), optionally 35-42 mol% sterol, for 5 example, 30-31 mol%, 31-32 mol%, 32-33 mol%, 33-34 mol%, 35-35 mol%, 35-36 mol%, 36-37 mol%, 37-38 mol%, 38-39 mol%, or 39-40 mol%, or 40-42 mol% sterol; (iii) 5-15 mol% helper lipid (e.g., DSPC), optionally 10-15 mol% helper lipid, for example, 5-6 mol%, 6-7 mol%, 7-8 mol%, 8-9 mol%, 9-10 mol%, 10-11 mol%, 11-12 mol%, 12-13 mol%, 13-14 mol%, or 14-15 mol% helper lipid; and (iv) 1-5% PEG lipid 10 (e.g., PEG-DMG), optionally 1-5 mol% PEG lipid, for example 1.5 to 2.5 mol%, 1-2 mol%, 2-3 mol%, 3-4 mol%, or 4-5 mol% PEG lipid. In some cases, the delivery agent comprises Cholesterol and DSPC. In some instances, a polynucleotide of the disclosure is an mRNA that comprises a 5′-terminal cap (e.g., m⁷Gp-ppGm-A, m⁷Gp-ppGm-A, or m⁷Gp-ppGm ), a 5′UTR (e.g., 15 SEQ ID NO: 7 or 56), an ORF sequence of SEQ ID NO: 8 or 9, a 3′UTR (e.g., SEQ ID NO:10-12 or 141), and a poly A tail (e.g., SEQ ID NO:117 or SEQ ID NO:13), wherein all uridines in the polynucleotide are N1-methylpseudouridines. The mRNA is formulated in a delivery vehicle for administration to a subject in need thereof. In some cases, the delivery agent comprises Compound II or Compound VI as the ionizable amino 20 lipid and PEG-DMG or Compound I as the PEG lipid. In some cases, the delivery agent comprises Compound B as the ionizable amino lipid and PEG-DMG or Compound I as the PEG lipid. In certain instances, the delivery vehicle is the LNP referred to herein as LNP2. 25 Signal Sequences The polynucleotides (e.g., a RNA, e.g., an mRNA) can also comprise nucleotide sequences that encode additional features that facilitate trafficking of the encoded polypeptides to therapeutically relevant sites. One such feature that aids in protein 47 Attorney Docket No.: 45817-0177WO1 / MTX980.20 trafficking is the signal sequence or targeting sequence. The peptides encoded by these signal sequences are known by a variety of names, including targeting peptides, transit peptides, and signal peptides. In some cases, the polynucleotide (e.g., a RNA, e.g., an mRNA) comprises a nucleotide sequence (e.g., an ORF) that encodes a signal peptide 5 operably linked to a nucleotide sequence that encodes a GPC3 binding CAR protein described herein. In some instances, the "signal sequence" or "signal peptide" is a polynucleotide or polypeptide, respectively, which is from about 30-210, e.g., about 45-80 or 15-60 nucleotides (e.g., about 20, 30, 40, 50, 60, or 70 amino acids) in length that, optionally, is 10 incorporated at the 5′ (or N-terminus) of the coding region or the polypeptide, respectively. Addition of these sequences results in trafficking the encoded polypeptide to a desired site, such as the endoplasmic reticulum or the mitochondria through one or more targeting pathways. Some signal peptides are cleaved from the protein, for example by a signal peptidase after the proteins are transported to the desired site. Non-limiting 15 examples of signal peptides are provided in Owji et al., European Journal of Cell Biology, 97(6):422-441 (2018); O’Neill et al., ACS Synth. Biol., 12, 8, 2339–2352 (2023). In certain instances, the polynucleotide of the disclosure comprises a nucleotide sequence encoding a GPC3 binding CAR protein described herein, wherein the 20 nucleotide sequence further comprises a 5′ nucleic acid sequence encoding a signal peptide. In some instances, the signal peptide is a heterologous signal peptide. In some cases, the signal peptide comprises any one of the following amino acid sequences: MALPVTALLLPLALLLHAARP (SEQ ID NO:1), MLLLVTSLLLCELPHPAFLLIP (SEQ ID NO: 48), 25 MLVMAPRTVLLLLSAALALTETWAG (SEQ ID NO:49), M^{RVTAPRTLILLLSGALALTETWA (SEQ ID NO:50)} _, MLKNKKFKLNFIALTVAYALAPYTEA (SEQ ID NO:51), MGVKVLFALICIAVAEA (SEQ ID NO:52), or METPAQLLFLLLLWLPDTTG (SEQ ID NO:53). In one case, the signal peptide comprises or consists of the sequence set forth in SEQ ID NO:1. 48 Attorney Docket No.: 45817-0177WO1 / MTX980.20 Sequence-Optimized Nucleotide Sequences Encoding GPC3 binding CAR Proteins In some instances, the polynucleotide comprises a sequence-optimized nucleotide sequence encoding a GPC3 binding CAR protein disclosed herein. In some cases, the 5 polynucleotide of the disclosure comprises an open reading frame (ORF) encoding a GPC3 binding CAR protein, wherein the ORF has been sequence optimized. In some cases, the sequence optimized sequence that encodes a GPC3 binding CAR polypeptide described herein is used to practice the methods disclosed herein. In some instances, a polynucleotide of the present disclosure, for example a 10 polynucleotide comprising an mRNA nucleotide sequence encoding a GPC3 binding CAR protein described herein, comprises from 5′ to 3′ end: (i) a 5′ cap such as provided herein, for example, m⁷GpppGm, m⁷GpppGm-A, or m⁷GpppGm-AG; (ii) a 5′ UTR comprising a nucleotide sequence, e.g., set forth in SEQ ID NO: 7 or 15 56; (iii) an open reading frame encoding a GPC3 binding CAR protein of the disclosure, e.g., a sequence optimized nucleic acid sequence encoding the GPC3 binding CAR protein (e.g., SEQ ID NO:8 or 9); (iv) at least one stop codon (if not already present at 5′ terminus of 3′UTR); 20 (v) a 3′ UTR comprising a nucleotide sequence, e.g., set forth in SEQ ID NO:10; and (vi) a poly A tail (e.g., about 100 nt in length) (e.g., SEQ ID NO:13 or SEQ ID NO:117). In some cases, a polynucleotide of the present disclosure, for example a 25 polynucleotide comprising an mRNA nucleotide sequence encoding a GPC3 binding CAR protein of the disclosure, comprises from 5′ to 3′ end: (i) a 5′ cap such as provided herein, for example, m⁷GpppGm, m⁷GpppGm-A, or m⁷GpppGm-AG; 49 Attorney Docket No.: 45817-0177WO1 / MTX980.20 (ii) a 5′ UTR comprising the nucleotide sequence set forth in SEQ ID NO: 7 or 56; (iii) an open reading frame encoding a GPC3 binding CAR protein of the disclosure, e.g., a sequence optimized nucleic acid sequence encoding the GPC3 binding 5 CAR protein (e.g., SEQ ID NO: 8 or 9); (iv) at least one stop codon (if not present at 5′ terminus of 3′UTR); (v) a 3′ UTR comprising a nucleotide sequence set forth in SEQ ID NO:11; and (vi) a poly A tail (e.g., about 100 nt in length) (e.g., SEQ ID NO:13 or SEQ ID NO:117). 10 In some cases, a polynucleotide of the present disclosure, for example a polynucleotide comprising an mRNA nucleotide sequence encoding a GPC3 binding CAR protein of the disclosure, comprises from 5′ to 3′ end: (i) a 5′ cap such as provided herein, for example, m⁷GpppGm, m⁷GpppGm-A, or m⁷GpppGm-AG; 15 (ii) a 5′ UTR comprising the nucleotide sequence set forth in SEQ ID NO: 7 or 56; (iii) an open reading frame encoding a GPC3 binding CAR protein of the disclosure, e.g., a sequence optimized nucleic acid sequence encoding the GPC3 binding CAR protein (e.g., SEQ ID NO: 8 or 9); 20 (iv) at least one stop codon (if not present at 5′ terminus of 3′UTR); (v) a 3′ UTR comprising a nucleotide sequence set forth in SEQ ID NO:12; and (vi) a poly A tail (e.g., about 100 nt in length) (e.g., SEQ ID NO:13 or SEQ ID NO:117). In some cases, a polynucleotide of the present disclosure, for example a 25 polynucleotide comprising an mRNA nucleotide sequence encoding a GPC3 binding CAR protein of the disclosure, comprises from 5′ to 3′ end: (i) a 5′ cap such as provided herein, for example, m⁷GpppGm, m⁷GpppGm-A, or m⁷GpppGm-AG; 50 Attorney Docket No.: 45817-0177WO1 / MTX980.20 (ii) a 5′ UTR comprising the nucleotide sequence set forth in SEQ ID NO: 7 or 56; (iii) an open reading frame encoding a GPC3 binding CAR protein of the disclosure, e.g., a sequence optimized nucleic acid sequence encoding the GPC3 binding 5 CAR protein (e.g., SEQ ID NO: 8 or 9); (iv) at least one stop codon (if not present at 5′ terminus of 3′UTR); (v) a 3′ UTR comprising a nucleotide sequence set forth in SEQ ID NO:141; and (vi) a poly A tail (e.g., about 100 nt in length) (e.g., SEQ ID NO:13 or SEQ ID NO:117). 10 In certain cases, all uridines in the polynucleotide are N1-methylpseudouridines. In some cases, all uridines in the polynucleotide are 5-methoxyuridines. The sequence-optimized nucleotide sequences disclosed herein are distinct from the corresponding wild type nucleotide acid sequences and from other known sequence- optimized nucleotide sequences, e.g., these sequence-optimized nucleic acids have 15 unique compositional characteristics. In some cases, the percentage of uracil or thymine nucleobases in a sequence- optimized nucleotide sequence (e.g., encoding a GPC3 binding CAR protein described herein) is modified (e.g., reduced) with respect to the percentage of uracil or thymine nucleobases in the reference wild-type nucleotide sequence. Such a sequence is referred 20 to as a uracil-modified or thymine-modified sequence. The percentage of uracil or thymine content in a nucleotide sequence can be determined by dividing the number of uracils or thymines in a sequence by the total number of nucleotides and multiplying by 100. In some cases, the sequence-optimized nucleotide sequence has a lower uracil or thymine content than the uracil or thymine content in the reference wild-type sequence. 25 In some cases, the uracil or thymine content in a sequence-optimized nucleotide sequence of the disclosure is greater than the uracil or thymine content in the reference wild-type sequence and still maintain beneficial effects, e.g., increased expression and/or reduced Toll-Like Receptor (TLR) response when compared to the reference wild-type sequence. 51 Attorney Docket No.: 45817-0177WO1 / MTX980.20 Methods for optimizing codon usage are known in the art. For example, an ORF of any one or more of the sequences provided herein may be codon optimized. Codon optimization, in some cases, may be used to match codon frequencies in target and host organisms to ensure proper folding; bias GC content to increase mRNA stability or 5 reduce secondary structures; minimize tandem repeat codons or base runs that may impair gene construction or expression; customize transcriptional and translational control regions; insert or remove protein trafficking sequences; remove/add post translation modification sites in encoded protein (e.g., glycosylation sites); add, remove or shuffle protein domains; insert or delete restriction sites; modify ribosome binding 10 sites and mRNA degradation sites; adjust translational rates to allow the various domains of the protein to fold properly; or reduce or eliminate problem secondary structures within the polynucleotide. Codon optimization tools, algorithms and services are known in the art - non-limiting examples include services from GeneArt (Life Technologies), DNA2.0 (Menlo Park CA) and/or proprietary methods. In some cases, the open reading 15 frame (ORF) sequence is optimized using optimization algorithms. Identification and Ratio Determination (IDR) Sequences In some aspects, a polynucleotide of this disclosure (e.g., an mRNA) comprises an Identification and Ratio Determination (IDR) sequence. An IDR sequence is a sequence 20 of a biological molecule (e.g., nucleic acid or protein) that, when combined with the sequence of a target biological molecule, serves to identify the target biological molecule. Typically, an IDR sequence is a heterologous sequence that is incorporated within or appended to a sequence of a target biological molecule and can be used as a reference to identify the target molecule. Thus, in some cases, a nucleic acid (e.g., mRNA) comprises 25 (i) a target sequence of interest (e.g., a coding sequence encoding a therapeutic and/or antigenic peptide or protein); and (ii) a unique IDR sequence. An RNA species (e.g., RNA having a given coding sequence) may comprise an IDR sequence that differs from the IDR sequence of other RNA species (e.g., RNA(s) having different coding sequence(s)). Each IDR sequence thus identifies a particular 52 Attorney Docket No.: 45817-0177WO1 / MTX980.20 RNA species, and so the abundance of IDR sequences may be measured to determine the abundance of each RNA species in a composition. Use of distinct IDR sequences to identify RNA species allows for analysis of multivalent RNA compositions (e.g., containing multiple RNA species) containing RNA species with similar coding sequences 5 and/or lengths, which could otherwise be difficult to distinguish using PCR- or chromatography-based analysis of full-length RNAs. Each RNA species in a multivalent RNA composition may comprise an IDR sequence that is not a sequence isomer of an IDR sequence of another RNA species in a multivalent RNA composition (e.g., the IDR sequence does not have the same number of 10 adenosine nucleotides, the same number of cytosine nucleotides, the same number of guanine nucleotides, and the same number of uracil nucleotides, as another IDR sequence in the composition, even if those sequences have different sequences). Having identical nucleotide compositions causes sequence isomers to have the same mass, presenting a challenge to distinguishing sequence isomers using mass-based identification methods 15 (e.g., mass spectrometry). Each RNA species in a multivalent RNA composition may comprise an IDR sequence having a mass that differs from the mass of IDR sequences of each other RNA species in a multivalent RNA composition. For example, the mass of each IDR sequence may differ from the mass of other IDR sequences by at least 9 Da, at least 25 Da, at least 20 25 Da, or at least 50 Da. Use of IDR sequences with distinct masses allows RNA fragments comprising different IDR sequences to be distinguished using mass-based analysis methods (e.g., mass spectrometry), which do not require reverse transcription, amplification, or sequencing of RNAs. Each RNA species in an RNA composition may comprises an IDR sequence with 25 a different length. For example, each IDR sequence may have a length independently selected from 0 to 25 nucleotides. The length of a nucleic acid influences the rate at which the nucleic acid traverses a chromatography column, and so the use of IDR sequences of different lengths on different RNA species allows RNA fragments having 53 Attorney Docket No.: 45817-0177WO1 / MTX980.20 different IDR sequences to be distinguished using chromatography-based methods (e.g., LC-UV). IDR sequences may be chosen such that no IDR sequence comprises a start codon, ‘AUG’. Lack of a start codon in an IDR sequence prevents undesired translation 5 of nucleotide sequences within and/or downstream from the IDR sequence. IDR sequences may be chosen such that no IDR sequence comprises a recognition site for a restriction enzyme. In one example, no IDR sequence comprises a recognition site for XbaI, ‘UCUAG’. Lack of a recognition site for a restriction enzyme (e.g., XbaI recognition site ‘UCUAG’) allows the restriction enzyme to be used in generating and 10 modifying a DNA template for in vitro transcription, without affecting the IDR sequence or sequence of the transcribed RNA. In some cases, the IDR sequence may be inserted in a 3’UTR and/or a poly A tail. In some instances, the IDR sequence is inserted in a 3’UTR. In one case, the IDR sequence consists of 15 nucleotides (e.g., AGAAAUAAAUUAAUU (SEQ ID NO:54)). 15 In another case, the IDR sequence consists of 9 to 15 nucleotides, wherein no IDR sequence comprises a recognition site for a restriction enzyme. In one instance, the 3’UTR with an IDR is shown below: UAAAGCUCCCCGGGGCAAACACCAUUGUCACACUCCAGCCUCGGUGGCCUAGCCAAACA CCAUUGUCACACUCCAUUCUUGCCCCUUGGGCCCAAACACCAUUGUCACACUCCAUCCC 20 CCCAGCCCCUCCUCCCCUUCCUGCA(X)nGUGGUCUUUGAAUAAAGUCUGAGUGGGCGG C (SEQ ID NO:135), wherein n = 9 to 15 and wherein each X is independently an A, U, C, or G. Modified Nucleotide Sequences Encoding GPC3 binding CAR Proteins 25 In some instances, the polynucleotide (e.g., a RNA, e.g., an mRNA) comprises a chemically modified nucleobase, for example, a chemically modified uracil, e.g., pseudouracil, N1-methylpseudouracil, 5-methoxyuracil, or the like. In some cases, the mRNA is a uracil-modified sequence comprising an ORF encoding a GPC3 binding CAR protein described herein, wherein the mRNA comprises a chemically modified 54 Attorney Docket No.: 45817-0177WO1 / MTX980.20 nucleobase, for example, a chemically modified uracil, e.g., pseudouracil, N1-methylpseudouracil, or 5-methoxyuracil. In certain aspects of the disclosure, when the modified uracil base is connected to a ribose sugar, as it is in polynucleotides, the resulting modified nucleoside or nucleotide 5 is referred to as modified uridine. In some cases, uracil in the polynucleotide is at least about 25%, at least about 30%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least 90%, at least 95%, at least 99%, or about 100% modified uracil. In one case, uracil in the polynucleotide is at least 95% modified uracil. In another case, uracil in the polynucleotide is 100% modified uracil. In one case, 10 all uracils in the polynucleotide are N1-methylpseudouracil. In instances where uracil in the polynucleotide is at least 95% modified uracil overall uracil content can be adjusted such that an mRNA provides suitable protein expression levels while inducing little to no immune response. In some cases, the uracil content of the ORF is between about 100% and about 150%, between about 100% and 15 about 110%, between about 105% and about 115%, between about 110% and about 120%, between about 115% and about 125%, between about 120% and about 130%, between about 125% and about 135%, between about 130% and about 140%, between about 135% and about 145%, between about 140% and about 150% of the theoretical minimum uracil content in the corresponding wild-type ORF (%U_TM). In other cases, the 20 uracil content of the ORF is between about 121% and about 136% or between 123% and 134% of the %UTM. In some cases, the uracil content of the ORF encoding a GPC3 binding CAR protein described herein is about 115%, about 120%, about 125%, about 130%, about 135%, about 140%, about 145%, or about 150% of the %U_TM. In this context, the term "uracil" can refer to modified uracil and/or naturally occurring uracil. 25 In some instances, the uracil content in the ORF of the mRNA encoding a GPC3 binding CAR protein of the disclosure is less than about 30%, about 25%, about 20%, about 15%, or about 10% of the total nucleobase content in the ORF. In some cases, the uracil content in the ORF is between about 10% and about 20% of the total nucleobase content in the ORF. In other cases, the uracil content in the ORF is between about 10% 55 Attorney Docket No.: 45817-0177WO1 / MTX980.20 and about 25% of the total nucleobase content in the ORF. In one case, the uracil content in the ORF of the mRNA encoding a GPC3 binding CAR protein described herein is less than about 20% of the total nucleobase content in the open reading frame. In this context, the term "uracil" can refer to modified uracil and/or naturally occurring uracil. 5 In further instances, the ORF of the mRNA encoding a GPC3 binding CAR protein having modified uracil and adjusted uracil content has increased Cytosine (C), Guanine (G), or Guanine/Cytosine (G/C) content (absolute or relative). In some cases, the overall increase in C, G, or G/C content (absolute or relative) of the ORF is at least about 2%, at least about 3%, at least about 4%, at least about 5%, at least about 6%, at 10 least about 7%, at least about 10%, at least about 15%, at least about 20%, at least about 40%, at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 90%, at least about 95%, or at least about 100% relative to the G/C content (absolute or relative) of the wild-type ORF. In some cases, the G, the C, or the G/C content in the ORF is less than about 100%, less than about 90%, less than about 85%, or 15 less than about 80% of the theoretical maximum G, C, or G/C content of the corresponding wild type nucleotide sequence encoding the GPC3 binding CAR protein (%G_TMX; %C_TMX, or %G/C_TMX). In some cases, the increases in G and/or C content (absolute or relative) described herein can be conducted by replacing synonymous codons with low G, C, or G/C content with synonymous codons having higher G, C, or G/C 20 content. In other cases, the increase in G and/or C content (absolute or relative) is conducted by replacing a codon ending with U with a synonymous codon ending with G or C. In further instances, the ORF of the mRNA encoding a GPC3 binding CAR protein of the disclosure comprises modified uracil and has an adjusted uracil content 25 containing less uracil pairs (UU) and/or uracil triplets (UUU) and/or uracil quadruplets (UUUU) than the corresponding wild-type nucleotide sequence encoding the GPC3 binding CAR protein. In some cases, the ORF of the mRNA encoding a GPC3 binding CAR protein of the disclosure contains no uracil pairs and/or uracil triplets and/or uracil quadruplets. In some cases, uracil pairs and/or uracil triplets and/or uracil quadruplets 56 Attorney Docket No.: 45817-0177WO1 / MTX980.20 are reduced below a certain threshold, e.g., no more than 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 occurrences in the ORF of the mRNA encoding the GPC3 binding CAR protein. In a particular instance, the ORF of the mRNA encoding the GPC3 binding CAR protein of the disclosure contains less than 20, 19, 18, 17, 16, 15, 5 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, or 1 non-phenylalanine uracil pairs and/or triplets. In another case, the ORF of the mRNA encoding a GPC3 binding CAR protein of the disclosure contains no non-phenylalanine uracil pairs and/or triplets. In further instances, the ORF of the mRNA encoding a GPC3 binding CAR protein of the disclosure comprises modified uracil and has an adjusted uracil content 10 containing less uracil-rich clusters than the corresponding wild-type nucleotide sequence encoding the GPC3 binding CAR protein. In some instances, the ORF of the mRNA encoding the GPC3 binding CAR protein of the disclosure contains uracil-rich clusters that are shorter in length than corresponding uracil-rich clusters in the corresponding wild-type nucleotide sequence encoding the GPC3 binding CAR protein. 15 In further instances, alternative lower frequency codons are employed. At least about 5%, at least about 10%, at least about 15%, at least about 20%, at least about 25%, at least about 30%, at least about 35%, at least about 40%, at least about 45%, at least about 50%, at least about 55%, at least about 60%, at least about 65%, at least about 70%, at least about 75%, at least about 80%, at least about 85%, at least about 90%, at least20 about 95%, at least about 99%, or 100% of the codons in the GPC3 binding CAR protein- encoding ORF of the modified uracil-comprising mRNA are substituted with alternative codons, each alternative codon having a codon frequency lower than the codon frequency of the substituted codon in the synonymous codon set. The ORF also has adjusted uracil content, as described above. In some cases, at least one codon in the ORF of the mRNA 25 encoding the GPC3 binding CAR protein is substituted with an alternative codon having a codon frequency lower than the codon frequency of the substituted codon in the synonymous codon set. In some cases, the adjusted uracil content, GPC3 binding CAR protein-encoding ORF of the modified uracil-comprising mRNA exhibits expression levels of a GPC3 57 Attorney Docket No.: 45817-0177WO1 / MTX980.20 binding CAR protein when administered to a mammalian cell that are higher than expression levels of the GPC3 binding CAR protein from the corresponding wild-type mRNA. In some cases, the mammalian cell is a mouse cell, a rat cell, or a rabbit cell. In other cases, the mammalian cell is a monkey cell or a human cell. In some cases, the 5 human cell is a HeLa cell, a BJ fibroblast cell, or a peripheral blood mononuclear cell (PBMC). In some cases, the GPC3 binding CAR protein is expressed at a level higher than expression levels of the GPC3 binding CAR protein from the corresponding wild- type mRNA when the mRNA is administered to a mammalian cell in vivo. In some cases, the mRNA is administered to mice, rabbits, rats, pigs, horses, cows, dogs, cats, 10 monkeys, or humans. In some cases, the mRNA is administered intravenously, subcutaneously, or intramuscularly. In other cases, the GPC3 binding CAR protein is expressed when the mRNA is administered to a mammalian cell in vitro. In some cases, the expression is increased by at least about 2-fold, at least about 5-fold, at least about 10- fold, at least about 50-fold, at least about 500-fold, at least about 1500-fold, or at least 15 about 3000-fold. In other cases, the expression is increased by at least about 10%, about 20%, about 30%, about 40%, about 50%, 60%, about 70%, about 80%, about 90%, or about 100%. In some instances, adjusted uracil content, GPC3 binding CAR protein-encoding ORF of the modified uracil-comprising mRNA exhibits increased stability. In some 20 cases, the mRNA exhibits increased stability in a cell relative to the stability of a corresponding wild-type mRNA under the same conditions. In some cases, the mRNA exhibits increased stability including resistance to nucleases, thermal stability, and/or increased stabilization of secondary structure. In some cases, increased stability exhibited by the mRNA is measured by determining the half-life of the mRNA (e.g., in a 25 plasma, serum, cell, or tissue sample) and/or determining the area under the curve (AUC) of the protein expression by the mRNA over time (e.g., in vitro or in vivo). An mRNA is identified as having increased stability if the half-life and/or the AUC is greater than the half-life and/or the AUC of a corresponding wild-type mRNA under the same conditions. 58 Attorney Docket No.: 45817-0177WO1 / MTX980.20 In some cases, the mRNA of the present disclosure induces a detectably lower immune response (e.g., innate or acquired) relative to the immune response induced by a corresponding wild-type mRNA under the same conditions. In other cases, the mRNA of the present disclosure induces a detectably lower immune response (e.g., innate or 5 acquired) relative to the immune response induced by an mRNA that encodes for a GPC3 binding CAR protein but does not comprise modified uracil under the same conditions, or relative to the immune response induced by an mRNA that encodes for a GPC3 binding CAR protein and that comprises modified uracil but that does not have adjusted uracil content under the same conditions. The innate immune response can be manifested by 10 increased expression of pro-inflammatory cytokines, activation of intracellular PRRs (RIG-I, MDA5, etc.), cell death, and/or termination or reduction in protein translation. In some cases, a reduction in the innate immune response can be measured by expression or activity level of Type 1 interferons (e.g., IFN-α, IFN-β, IFN-κ, IFN-δ, IFN-ε, IFN-τ, IFN- ω, and IFN-ζ) or the expression of interferon-regulated genes such as the toll-like 15 receptors (e.g., TLR7 and TLR8), and/or by decreased cell death following one or more administrations of the mRNA of the disclosure into a cell. In some cases, the expression of Type-1 interferons by a mammalian cell in response to the mRNA of the present disclosure is reduced by at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 99%, 99.9%, or greater than 99.9% relative to a 20 corresponding wild-type mRNA, to an mRNA that encodes a GPC3 binding CAR protein of the disclosure but does not comprise modified uracil, or to an mRNA that encodes a GPC3 binding CAR protein and that comprises modified uracil but that does not have adjusted uracil content. In cases, the interferon is IFN-β. In some cases, cell death frequency caused by administration of mRNA of the present disclosure to a mammalian 25 cell is 10%, 25%, 50%, 75%, 85%, 90%, 95%, or over 95% less than the cell death frequency observed with a corresponding wild-type mRNA, an mRNA that encodes for a GPC3 binding CAR protein but does not comprise modified uracil, or mRNA that encodes for a GPC3 binding CAR protein and that comprises modified uracil but that does not have adjusted uracil content. In some cases, the mammalian cell is a BJ 59 Attorney Docket No.: 45817-0177WO1 / MTX980.20 fibroblast cell. In other cases, the mammalian cell is a splenocyte. In some cases, the mammalian cell is that of a mouse or a rat. In other cases, the mammalian cell is that of a human. In one case, the mRNA of the present disclosure does not substantially induce an innate immune response of a mammalian cell into which the mRNA is introduced. 5 Methods for Modifying Polynucleotides The disclosure includes modified polynucleotides comprising a polynucleotide described herein (e.g., a polynucleotide, e.g. mRNA, comprising a nucleotide sequence encoding a GPC3 binding CAR protein described herein. The modified polynucleotides 10 can be chemically modified and/or structurally modified. When the polynucleotides are chemically and/or structurally modified the polynucleotides can be referred to as "modified polynucleotides." The present disclosure provides for modified nucleosides and nucleotides of a polynucleotide (e.g., RNA polynucleotides, such as mRNA polynucleotides) encoding a 15 GPC3 binding CAR protein of the disclosure. A "nucleoside" refers to a compound containing a sugar molecule (e.g., a pentose or ribose) or a derivative thereof in combination with an organic base (e.g., a purine or pyrimidine) or a derivative thereof (also referred to herein as "nucleobase"). A “nucleotide" refers to a nucleoside including a phosphate group. Modified nucleotides can be synthesized by any useful method, such 20 as, for example, chemically, enzymatically, or recombinantly, to include one or more modified or non-natural nucleosides. Polynucleotides can comprise a region or regions of linked nucleosides. Such regions can have variable backbone linkages. The linkages can be standard phosphodiester linkages, in which case the polynucleotides would comprise regions of nucleotides. 25 The modified polynucleotides disclosed herein can comprise various distinct modifications. In some instances, the modified polynucleotides contain one, two, or more (optionally different) nucleoside or nucleotide modifications. In some instances, a modified polynucleotide, introduced to a cell can exhibit one or more desirable 60 Attorney Docket No.: 45817-0177WO1 / MTX980.20 properties, e.g., improved protein expression, reduced immunogenicity, or reduced degradation in the cell, as compared to an unmodified polynucleotide. In some instances, a polynucleotide of the present disclosure (e.g., a polynucleotide comprising a nucleotide sequence encoding a GPC3 binding CAR protein 5 of the disclosure) is structurally modified. As used herein, a "structural" modification is one in which two or more linked nucleosides are inserted, deleted, duplicated, inverted or randomized in a polynucleotide without significant chemical modification to the nucleotides themselves. Because chemical bonds will necessarily be broken and reformed to effect a structural modification, structural modifications are of a chemical nature and 10 hence are chemical modifications. However, structural modifications will result in a different sequence of nucleotides. For example, the polynucleotide "ATCG" can be chemically modified to "AT-5meC-G". The same polynucleotide can be structurally modified from "ATCG" to "ATCCCG". Here, the dinucleotide "CC" has been inserted, resulting in a structural modification to the polynucleotide. 15 Therapeutic compositions of the present disclosure comprise, in some cases, at least one nucleic acid (e.g., RNA) having an open reading frame encoding a GPC3 binding CAR protein of the disclosure, wherein the nucleic acid comprises nucleotides and/or nucleosides that can be standard (unmodified) or modified as is known in the art. In some instances, nucleotides and nucleosides of the present disclosure comprise 20 modified nucleotides or nucleosides. Such modified nucleotides and nucleosides can be naturally-occurring modified nucleotides and nucleosides or non-naturally occurring modified nucleotides and nucleosides. Such modifications can include those at the sugar, backbone, or nucleobase portion of the nucleotide and/or nucleoside as are recognized in the art. 25 In some instances, a naturally-occurring modified nucleotide or nucleotide of the disclosure is one as is generally known or recognized in the art. Non-limiting examples of such naturally occurring modified nucleotides and nucleotides can be found, inter alia, in the widely recognized MODOMICS database. 61 Attorney Docket No.: 45817-0177WO1 / MTX980.20 In some instances, a non-naturally occurring modified nucleotide or nucleoside of the disclosure is one as is generally known or recognized in the art. Non-limiting examples of such non-naturally occurring modified nucleotides and nucleosides can be found, inter alia, in published US application Nos. PCT/US2012/058519; 5 PCT/US2013/075177; PCT/US2014/058897; PCT/US2014/058891; PCT/US2014/070413; PCT/US2015/36773; PCT/US2015/36759; PCT/US2015/36771; or PCT/IB2017/051367 all of which are incorporated by reference herein. In some instances, at least one RNA (e.g., mRNA) of the present disclosure is not chemically modified and comprises the standard ribonucleotides consisting of adenosine, 10 guanosine, cytosine and uridine. In some cases, nucleotides and nucleosides of the present disclosure comprise standard nucleoside residues such as those present in transcribed RNA (e.g. A, G, C, or U). In some cases, nucleotides and nucleosides of the present disclosure comprise standard deoxyribonucleosides such as those present in DNA (e.g. dA, dG, dC, or dT). 15 Hence, nucleic acids of the disclosure (e.g., DNA nucleic acids and RNA nucleic acids, such as mRNA nucleic acids) can comprise standard nucleotides and nucleosides, naturally-occurring nucleotides and nucleosides, non-naturally-occurring nucleotides and nucleosides, or any combination thereof. Nucleic acids of the disclosure (e.g., DNA nucleic acids and RNA nucleic acids, 20 such as mRNA nucleic acids), in some instances, comprise various (more than one) different types of standard and/or modified nucleotides and nucleosides. In some cases, a particular region of a nucleic acid contains one, two or more (optionally different) types of standard and/or modified nucleotides and nucleosides. In some cases, a modified RNA nucleic acid (e.g., a modified mRNA nucleic 25 acid), introduced to a cell or organism, exhibits reduced degradation in the cell or organism, respectively, relative to an unmodified nucleic acid comprising standard nucleotides and nucleosides. In some cases, a modified RNA nucleic acid (e.g., a modified mRNA nucleic acid), introduced into a cell or organism, may exhibit reduced immunogenicity in the cell 62 Attorney Docket No.: 45817-0177WO1 / MTX980.20 or organism, respectively (e.g., a reduced innate response) relative to an unmodified nucleic acid comprising standard nucleotides and nucleosides. Nucleic acids (e.g., RNA nucleic acids, such as mRNA nucleic acids), in some cases, comprise non-natural modified nucleotides that are introduced during synthesis or 5 post-synthesis of the nucleic acids to achieve desired functions or properties. The modifications may be present on internucleotide linkages, purine or pyrimidine bases, or sugars. The modification may be introduced with chemical synthesis or with a polymerase enzyme at the terminal of a chain or anywhere else in the chain. Any of the regions of a nucleic acid may be chemically modified. 10 The present disclosure provides for modified nucleosides and nucleotides of a nucleic acid (e.g., RNA nucleic acids, such as mRNA nucleic acids). A “nucleoside” refers to a compound containing a sugar molecule (e.g., a pentose or ribose) or a derivative thereof in combination with an organic base (e.g., a purine or pyrimidine) or a derivative thereof (also referred to herein as “nucleobase”). A “nucleotide” refers to a nucleoside, including 15 a phosphate group. Modified nucleotides may by synthesized by any useful method, such as, for example, chemically, enzymatically, or recombinantly, to include one or more modified or non-natural nucleosides. Nucleic acids can comprise a region or regions of linked nucleosides. Such regions may have variable backbone linkages. The linkages can be standard phosphodiester linkages, in which case the nucleic acids would comprise 20 regions of nucleotides. Modified nucleotide base pairing encompasses not only the standard adenosine- thymine, adenosine-uracil, or guanosine-cytosine base pairs, but also base pairs formed between nucleotides and/or modified nucleotides comprising non-standard or modified bases, wherein the arrangement of hydrogen bond donors and hydrogen bond acceptors 25 permits hydrogen bonding between a non-standard base and a standard base or between two complementary non-standard base structures, such as, for example, in those nucleic acids having at least one chemical modification. One example of such non-standard base pairing is the base pairing between the modified nucleotide inosine and adenine, cytosine 63 Attorney Docket No.: 45817-0177WO1 / MTX980.20 or uracil. Any combination of base/sugar or linker may be incorporated into nucleic acids of the present disclosure. In some instances, modified nucleobases in nucleic acids (e.g., RNA nucleic acids, such as mRNA nucleic acids) comprise N1-methyl-pseudouridine (m1ψ), 1-ethyl- 5 pseudouridine (e1ψ), 5-methoxy-uridine (mo5U), 5-methyl-cytidine (m5C), and/or pseudouridine (ψ). In some instances, modified nucleobases in nucleic acids (e.g., RNA nucleic acids, such as mRNA nucleic acids) comprise 5-methoxymethyl uridine, 5- methylthio uridine, 1-methoxymethyl pseudouridine, 5-methyl cytidine, and/or 5- methoxy cytidine. In some instances, the polyribonucleotide includes a combination of at 10 least two (e.g., 2, 3, 4 or more) of any of the aforementioned modified nucleobases, including but not limited to chemical modifications. In some cases, a RNA nucleic acid of the disclosure comprises N1-methyl- pseudouridine (m1ψ) substitutions at one or more or all uridine positions of the nucleic acid. 15 In some instances, a RNA nucleic acid of the disclosure comprises N1-methyl- pseudouridine (m1ψ) substitutions at one or more or all uridine positions of the nucleic acid and 5-methyl cytidine substitutions at one or more or all cytidine positions of the nucleic acid. In some cases, a RNA nucleic acid of the disclosure comprises pseudouridine (ψ) 20 substitutions at one or more or all uridine positions of the nucleic acid. In some cases, a RNA nucleic acid of the disclosure comprises pseudouridine (ψ) substitutions at one or more or all uridine positions of the nucleic acid and 5-methyl cytidine substitutions at one or more or all cytidine positions of the nucleic acid. In some cases, a RNA nucleic acid of the disclosure comprises uridine at one or 25 more or all uridine positions of the nucleic acid. In some instances, nucleic acids (e.g., RNA nucleic acids, such as mRNA nucleic acids) are uniformly modified (e.g., fully modified, modified throughout the entire sequence) for a particular modification. For example, a nucleic acid can be uniformly modified with N1-methyl-pseudouridine, meaning that all uridine residues in the mRNA 64 Attorney Docket No.: 45817-0177WO1 / MTX980.20 sequence are replaced with N1-methyl-pseudouridine. Similarly, a nucleic acid can be uniformly modified for any type of nucleoside residue present in the sequence by replacement with a modified residue such as those set forth above. The nucleic acids of the present disclosure may be partially or fully modified 5 along the entire length of the molecule. For example, one or more or all or a given type of nucleotide (e.g., purine or pyrimidine, or any one or more or all of A, G, U, C) may be uniformly modified in a nucleic acid of the disclosure, or in a predetermined sequence region thereof (e.g., in the mRNA including or excluding the poly A tail). In some instances, all nucleotides X in a nucleic acid of the present disclosure (or in a sequence 10 region thereof) are modified nucleotides, wherein X may be any one of nucleotides A, G, U, C, or any one of the combinations A+G, A+U, A+C, G+U, G+C, U+C, A+G+U, A+G+C, G+U+C or A+G+C. The nucleic acid may contain from about 1% to about 100% modified nucleotides (either in relation to overall nucleotide content, or in relation to one or more types of 15 nucleotide, i.e., any one or more of A, G, U or C) or any intervening percentage (e.g., from 1% to 20%, from 1% to 25%, from 1% to 50%, from 1% to 60%, from 1% to 70%, from 1% to 80%, from 1% to 90%, from 1% to 95%, from 10% to 20%, from 10% to 25%, from 10% to 50%, from 10% to 60%, from 10% to 70%, from 10% to 80%, from 10% to 90%, from 10% to 95%, from 10% to 100%, from 20% to 25%, from 20% to 20 50%, from 20% to 60%, from 20% to 70%, from 20% to 80%, from 20% to 90%, from 20% to 95%, from 20% to 100%, from 50% to 60%, from 50% to 70%, from 50% to 80%, from 50% to 90%, from 50% to 95%, from 50% to 100%, from 70% to 80%, from 70% to 90%, from 70% to 95%, from 70% to 100%, from 80% to 90%, from 80% to 95%, from 80% to 100%, from 90% to 95%, from 90% to 100%, and from 95% to 25 100%). It will be understood that any remaining percentage is accounted for by the presence of unmodified A, G, U, or C. The nucleic acids may contain at a minimum 1% and at maximum 100% modified nucleotides, or any intervening percentage, such as at least 5% modified nucleotides, at least 10% modified nucleotides, at least 25% modified nucleotides, at least 50% modified 65 Attorney Docket No.: 45817-0177WO1 / MTX980.20 nucleotides, at least 80% modified nucleotides, or at least 90% modified nucleotides. For example, the nucleic acids may contain a modified pyrimidine such as a modified uracil or cytosine. In some instances, at least 5%, at least 10%, at least 25%, at least 50%, at least 80%, at least 90% or 100% of the uracil in the nucleic acid is replaced with a 5 modified uracil (e.g., a 5-substituted uracil). The modified uracil can be replaced by a compound having a single unique structure, or can be replaced by a plurality of compounds having different structures (e.g., 2, 3, 4 or more unique structures). In some instances, at least 5%, at least 10%, at least 25%, at least 50%, at least 80%, at least 90% or 100% of the cytosine in the nucleic acid is replaced with a modified cytosine (e.g., a 5- 10 substituted cytosine). The modified cytosine can be replaced by a compound having a single unique structure, or can be replaced by a plurality of compounds having different structures (e.g., 2, 3, 4 or more unique structures). Untranslated Regions (UTRs) 15 Untranslated regions (UTRs) are nucleic acid sections of a polynucleotide before a start codon (5′ UTR) and after a stop codon (3′ UTR) that are not translated. In some instances, a polynucleotide (e.g., a ribonucleic acid (RNA), e.g., a messenger RNA (mRNA)) of the disclosure comprising an open reading frame (ORF) encoding a GPC3 binding CAR protein described herein further comprises UTRs (e.g., a 5′ UTR or 20 functional fragment thereof, a 3′ UTR or functional fragment thereof, or a combination thereof). A UTR (e.g., 5′ UTR or 3′ UTR) can be homologous or heterologous to the coding region in a polynucleotide. In some instances, the UTR is homologous to the ORF encoding the antigen. In some instances, the UTR is heterologous to the ORF 25 encoding the antigen. In some instances, the polynucleotide comprises two or more 5′ UTRs or functional fragments thereof, each of which has the same or different nucleotide sequences. In some instances, the polynucleotide comprises two or more 3′ UTRs or 66 Attorney Docket No.: 45817-0177WO1 / MTX980.20 functional fragments thereof, each of which has the same or different nucleotide sequences. In some instances, the 5′ UTR or functional fragment thereof, 3′ UTR or functional fragment thereof, or any combination thereof is sequence optimized. 5 In some instances, the 5′UTR or functional fragment thereof, 3′ UTR or functional fragment thereof, or any combination thereof comprises at least one chemically modified nucleobase, e.g., N1-methylpseudouracil or 5-methoxyuracil. UTRs can have features that provide a regulatory role, e.g., increased or decreased stability, localization and/or translation efficiency. A polynucleotide comprising a UTR 10 can be administered to a cell, tissue, or organism, and one or more regulatory features can be measured using routine methods. In some instances, a functional fragment of a 5′ UTR or 3′ UTR comprises one or more regulatory features of a full length 5′ or 3′ UTR, respectively. Natural 5′UTRs bear features that play roles in translation initiation. They harbor 15 signatures like Kozak sequences that are commonly known to be involved in the process by which the ribosome initiates translation of many genes. Kozak sequences have the consensus CCR(A/G)CCAUGG, where R is a purine (adenine or guanine) three bases upstream of the start codon (AUG), which is followed by another ‘G’.5′ UTRs also have been known to form secondary structures that are involved in elongation factor binding. 20 By engineering the features typically found in abundantly expressed genes of specific target organs, one can enhance the stability and protein production of a polynucleotide. For example, introduction of 5′ UTR of liver-expressed mRNA, such as albumin, serum amyloid A, Apolipoprotein A/B/E, transferrin, alpha fetoprotein, erythropoietin, or Factor VIII, can enhance expression of polynucleotides in hepatic cell lines or liver. Likewise, 25 use of 5′UTR from other tissue-specific mRNA to improve expression in that tissue is possible for muscle (e.g., MyoD, Myosin, Myoglobin, Myogenin, Herculin), for endothelial cells (e.g., Tie-1, CD36), for myeloid cells (e.g., C/EBP, AML1, G-CSF, GM-CSF, CD11b, MSR, Fr-1, i-NOS), for leukocytes (e.g., CD45, CD18), for adipose 67 Attorney Docket No.: 45817-0177WO1 / MTX980.20 tissue (e.g., CD36, GLUT4, ACRP30, adiponectin) and for lung epithelial cells (e.g., SP- A/B/C/D). In some instances, UTRs are selected from a family of transcripts whose proteins share a common function, structure, feature or property. For example, an encoded 5 polypeptide can belong to a family of proteins (i.e., that share at least one function, structure, feature, localization, origin, or expression pattern), which are expressed in a particular cell, tissue or at some time during development. The UTRs from any of the genes or mRNA can be swapped for any other UTR of the same or different family of proteins to create a new polynucleotide. 10 In some instances, the 5′ UTR and the 3′ UTR can be heterologous. In some instances, the 5′ UTR can be derived from a different species than the 3′ UTR. In some instances, the 3′ UTR can be derived from a different species than the 5′ UTR. Co-owned International Patent Application No. PCT/US2014/021522 (Publ. No. WO 2014/164253, incorporated herein by reference in its entirety) provides a listing of 15 exemplary UTRs that can be utilized in the polynucleotide of the present disclosure as flanking regions to an ORF. Additional exemplary UTRs of the application include, but are not limited to, one or more 5′UTR and/or 3′UTR derived from the nucleic acid sequence of: a globin, such as an α- or β-globin (e.g., a Xenopus, mouse, rabbit, or human globin); a strong Kozak 20 translational initiation signal; a CYBA (e.g., human cytochrome b-245 α polypeptide); an albumin (e.g., human albumin7); a HSD17B4 (hydroxysteroid (17-β) dehydrogenase); a virus (e.g., a tobacco etch virus (TEV), a Venezuelan equine encephalitis virus (VEEV), a Dengue virus, a cytomegalovirus (CMV) (e.g., CMV immediate early 1 (IE1)), a hepatitis virus (e.g., hepatitis B virus), a sindbis virus, or a PAV barley yellow dwarf virus); a heat 25 shock protein (e.g., hsp70); a translation initiation factor (e.g., elF4G); a glucose transporter (e.g., hGLUT1 (human glucose transporter 1)); an actin (e.g., human α or β actin); a GAPDH; a tubulin; a histone; a citric acid cycle enzyme; a topoisomerase (e.g., a 5′UTR of a TOP gene lacking the 5′ TOP motif (the oligopyrimidine tract)); a ribosomal protein Large 32 (L32); a ribosomal protein (e.g., human or mouse ribosomal protein, 68 Attorney Docket No.: 45817-0177WO1 / MTX980.20 such as, for example, rps9); an ATP synthase (e.g., ATP5A1 or the β subunit of mitochondrial H⁺-ATP synthase); a growth hormone e (e.g., bovine (bGH) or human (hGH)); an elongation factor (e.g., elongation factor 1 α1 (EEF1A1)); a manganese superoxide dismutase (MnSOD); a myocyte enhancer factor 2A (MEF2A); a β-F1- 5 ATPase, a creatine kinase, a myoglobin, a granulocyte-colony stimulating factor (G- CSF); a collagen (e.g., collagen type I, alpha 2 (Col1A2), collagen type I, alpha 1 (Col1A1), collagen type VI, alpha 2 (Col6A2), collagen type VI, alpha 1 (Col6A1)); a ribophorin (e.g., ribophorin I (RPNI)); a low density lipoprotein receptor-related protein (e.g., LRP1); a cardiotrophin-like cytokine factor (e.g., Nnt1); calreticulin (Calr); a 10 procollagen-lysine, 2-oxoglutarate 5-dioxygenase 1 (Plod1); and a nucleobindin (e.g., Nucb1). In some instances, the 5′ UTR is selected from the group consisting of a β-globin 5′ UTR; a 5′UTR containing a strong Kozak translational initiation signal; a cytochrome b-245 α polypeptide (CYBA) 5′ UTR; a hydroxysteroid (17-β) dehydrogenase 15 (HSD17B4) 5′ UTR; a Tobacco etch virus (TEV) 5′ UTR; a Venezuelan equine encephalitis virus (TEEV) 5′ UTR; a 5′ proximal open reading frame of rubella virus (RV) RNA encoding nonstructural proteins; a Dengue virus (DEN) 5′ UTR; a heat shock protein 70 (Hsp70) 5′ UTR; a eIF4G 5′ UTR; a GLUT15′ UTR; functional fragments thereof and any combination thereof. 20 In some instances, the 3′ UTR is selected from the group consisting of a β-globin 3′ UTR; a CYBA 3′ UTR; an albumin 3′ UTR; a growth hormone (GH) 3′ UTR; a VEEV 3′ UTR; a hepatitis B virus (HBV) 3′ UTR; α-globin 3′UTR; a DEN 3′ UTR; a PAV barley yellow dwarf virus (BYDV-PAV) 3′ UTR; an elongation factor 1 α1 (EEF1A1) 3′ UTR; a manganese superoxide dismutase (MnSOD) 3′ UTR; a β subunit of mitochondrial25 H(+)-ATP synthase (β-mRNA) 3′ UTR; a GLUT13′ UTR; a MEF2A 3′ UTR; a β-F1- ATPase 3′ UTR; functional fragments thereof and combinations thereof. Wild-type UTRs derived from any gene or mRNA can be incorporated into the polynucleotides of the disclosure. In some cases, a UTR can be altered relative to a wild type or native UTR to produce a variant UTR, e.g., by changing the orientation or 69 Attorney Docket No.: 45817-0177WO1 / MTX980.20 location of the UTR relative to the ORF; or by inclusion of additional nucleotides, deletion of nucleotides, swapping or transposition of nucleotides. In some cases, variants of 5′ or 3′ UTRs can be utilized, for example, mutants of wild type UTRs, or variants wherein one or more nucleotides are added to or removed from a terminus of the UTR. 5 Additionally, one or more synthetic UTRs can be used in combination with one or more non-synthetic UTRs. See, e.g., Mandal and Rossi, Nat. Protoc.20138(3):568-82, the contents of which are incorporated herein by reference in their entirety. UTRs or portions thereof can be placed in the same orientation as in the transcript from which they were selected or can be altered in orientation or location. Hence, a 5′ 10 and/or 3′ UTR can be inverted, shortened, lengthened, or combined with one or more other 5′ UTRs or 3′ UTRs. In some cases, the polynucleotide comprises multiple UTRs, e.g., a double, a triple or a quadruple 5′ UTR or 3′ UTR. For example, a double UTR comprises two copies of the same UTR either in series or substantially in series. For example, a double beta-globin 15 3′UTR can be used (see US2010/0129877, the contents of which are incorporated herein by reference in its entirety). The polynucleotides of the disclosure can comprise combinations of features. For example, the ORF can be flanked by a 5′UTR that comprises a strong Kozak translational initiation signal and/or a 3′UTR comprising an oligo(dT) sequence for templated addition 20 of a poly A tail. A 5′UTR can comprise a first polynucleotide fragment and a second polynucleotide fragment from the same and/or different UTRs (see, e.g., US2010/0293625, herein incorporated by reference in its entirety). Other non-UTR sequences can be used as regions or subregions within the polynucleotides of the disclosure. For example, introns or portions of intron sequences 25 can be incorporated into the polynucleotides of the disclosure. Incorporation of intronic sequences can increase protein production as well as polynucleotide expression levels. In some instances, the 3’UTR includes an IDR sequence(s). In some cases, the polynucleotide of the disclosure comprises an internal ribosome entry site (IRES) instead of or in addition to a UTR (see, e.g., Yakubov et al., Biochem. Biophys. Res. Commun. 70 Attorney Docket No.: 45817-0177WO1 / MTX980.20 2010394(1):189-193, the contents of which are incorporated herein by reference in their entirety). In some cases, the polynucleotide comprises an IRES instead of a 5′ UTR sequence. In some cases, the polynucleotide comprises an ORF and a viral capsid sequence. In some cases, the polynucleotide comprises a synthetic 5′ UTR in 5 combination with a non-synthetic 3′ UTR. In some cases, the UTR can also include at least one translation enhancer polynucleotide, translation enhancer element, or translational enhancer elements (collectively, "TEE," which refers to nucleic acid sequences that increase the amount of polypeptide or protein produced from a polynucleotide. As a non-limiting example, the 10 TEE can be located between the transcription promoter and the start codon. In some cases, the 5′ UTR comprises a TEE. In one case, a TEE is a conserved element in a UTR that can promote translational activity of a nucleic acid such as, but not limited to, cap-dependent or cap-independent translation. 15 5′ UTR sequences 5′ UTR sequences are important for ribosome recruitment to the mRNA and have been reported to play a role in translation (Hinnebusch A, et al., (2016) Science, 352:6292: 1413-6). 20 Disclosed herein, inter alia, is a polynucleotide, e.g., mRNA, comprising an open reading frame encoding a GPC3 binding CAR protein described herein, which polynucleotide has a 5′ UTR that confers an increased half-life, increased expression and/or increased activity of the polypeptide encoded by said polynucleotide, or of the polynucleotide itself. In an instance, a polynucleotide disclosed herein comprises: (a) a 5′-UTR (e.g., as 25 provided in Table 7 or a variant or fragment thereof); (b) a coding region comprising a stop element (e.g., as described herein); and (c) a 3′-UTR (e.g., as described herein), and LNP compositions comprising the same. In one instance, the polynucleotide comprises a 5′-UTR comprising a sequence provided in Table 7 or a variant or fragment thereof (e.g., 71 Attorney Docket No.: 45817-0177WO1 / MTX980.20 a functional variant or fragment thereof). In one instance, the polynucleotide comprises a 5′-UTR comprising the sequence of SEQ ID NO:56. In one instance, the polynucleotide having a 5′ UTR sequence provided in Table 7 or a variant or fragment thereof, has an increase in the half-life of the polynucleotide, e.g., 5 about 1.5-20-fold increase in half-life of the polynucleotide. In an instance, the increase in half-life is about 1.5, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20- fold, or more. In an instance, the increase in half-life is about 1.5-fold or more. In an instance, the increase in half-life is about 2-fold or more. In an instance, the increase in half-life is about 3-fold or more. In an instance, the increase in half-life is about 4-fold or 10 more. In an instance, the increase in half -life is about 5-fold or more. In one instance, the polynucleotide having a 5′ UTR sequence provided in Table 7 or a variant or fragment thereof, results in an increased level and/or activity, e.g., output, of the polypeptide encoded by the polynucleotide. In an instance, the 5′UTR results in about 1.5-20-fold increase in level and/or activity, e.g., output, of the 15 polypeptide encoded by the polynucleotide. In an instance, the increase in level and/or activity is about 1.5, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20-fold, or more. In one case, the increase in level and/or activity is about 1.5-fold or more. In one case, the increase in level and/or activity is about 2-fold or more. In another case, the increase in level and/or activity is about 3-fold or more. In another case, the increase in 20 level and/or activity is about 4-fold or more. In one case, the increase in level and/or activity is about 5-fold or more. In one instance, the increase is compared to an otherwise similar polynucleotide which does not have a 5′ UTR, has a different 5′ UTR, or does not have a 5′ UTR described in Table 7 or a variant or fragment thereof. 25 In one instance, the increase in half-life of the polynucleotide is measured according to an assay that measures the half-life of a polynucleotide. In one instance, the increase in level and/or activity, e.g., output, of the polypeptide encoded by the polynucleotide is measured according to an assay that measures the level and/or activity of a polypeptide. 72 Attorney Docket No.: 45817-0177WO1 / MTX980.20 In one instance, the 5′ UTR comprises a sequence provided in Table 7 or a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to a 5′ UTR sequence provided in Table 7, or a variant or a fragment thereof. In certain cases, the 5′ UTR comprises a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 5 99% or 100% identity to SEQ ID NO: 56, SEQ ID NO: 57, SEQ ID NO: 58, SEQ ID NO: 59, SEQ ID NO: 60, SEQ ID NO: 61, SEQ ID NO: 62, SEQ ID NO: 63, or SEQ ID NO: 64. In one instance, the 5′ UTR comprises a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to SEQ ID NO: 56. In another instance, the 10 5′ UTR comprises a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to SEQ ID NO: 7. In another instance, the 5′ UTR comprises a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to SEQ ID NO: 57. In yet another instance, the 5′ UTR comprises a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to SEQ ID NO: 58. In a further 15 instance, the 5′ UTR comprises a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to SEQ ID NO: 59. In another instance, the 5′ UTR comprises a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to SEQ ID NO: 60. In another instance, the 5′ UTR comprises a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to SEQ ID NO: 61. 20 In another instance, the 5′ UTR comprises a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to SEQ ID NO: 62. In another instance, the 5′ UTR comprises a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to SEQ ID NO: 63. In another instance, the 5′ UTR comprises a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to SEQ ID 25 NO: 64. In some cases, the 5′ UTR comprises the sequence of SEQ ID NO:56. In some cases, the 5′ UTR comprises the sequence of SEQ ID NO:86 with an added A or G nucleotide at the N-terminus. In one instance, the 5′ UTR comprises or consists of the sequence of SEQ ID NO:7. 73 Attorney Docket No.: 45817-0177WO1 / MTX980.20 In some instances, a 5′ UTR sequence provided in Table 7 has a added first nucleotide which is an A. For example, the 5’UTR of SEQ ID NO:56 with an added A as the first nucleotide is the 5’UTR provided in SEQ ID NO:7. In other instances, a 5′ UTR sequence provided in Table 7 (e.g., SEQ ID NO:56) has an added first nucleotide which 5 is a G. Table 7: 5′ UTR sequences SEQ ID Sequence Sequence NO U A C C U C A U 74 Attorney Docket No.: 45817-0177WO1 / MTX980.20 62 A11 GGAAAUAAGAGAGAAAAGAAGAGUAAGAAGAAAU (Reference AUAAGACCCCGGCGCCGCCACC U U U U n n C U U U 75 Attorney Docket No.: 45817-0177WO1 / MTX980.20 68 A13 GGAAAAUCUGUAUUAGGUUGGCGUGUUCUUUGGU CGGUUGUUAGUAUUGUUGUUGAUUCGUUUGUGGU C G A U A C G G G C G U U G U A 76 Attorney Docket No.: 45817-0177WO1 / MTX980.20 77 A22 GGAAAUCGUAGAGAGUCGUACUUACGUGGUCGCC AUUGCAUAGCGCGCGAAAGCAACAGGAACAAGAA G C U G G U U A U A G In one instance, the 5 UTR comprises a variant of SEQ ID NO: 56. In one instance, the variant of SEQ ID NO: 56 comprises a nucleic acid sequence of Formula A: 77 Attorney Docket No.: 45817-0177WO1 / MTX980.20 G G A A A U C G C A A A A (N2)X (N3)X C U (N4)X (N5)X C G C G U U A G A U U U C U U U U A G U U U U C U N6 N7 C A A C U A G C A A G C U U U U U G U U C U C G C C (N₈ C C)x (SEQ ID NO: 86), wherein: (N2)x is a uracil and x is an integer from 0 to 5, e.g., wherein x =3 or 4; 5 (N3)x is a guanine and x is an integer from 0 to 1; (N₄)_x is a cytosine and x is an integer from 0 to 1; (N₅)_x is a uracil and x is an integer from 0 to 5, e.g., wherein x =2 or 3; N6 is a uracil or cytosine; N₇ is a uracil or guanine; 10 N₈ is adenine or guanine and x is an integer from 0 to 1. In some cases, SEQ ID NO:86 includes an additional G nucleotide at the N- terminus. In some cases, SEQ ID NO:86 includes an A nucleotide at the N-terminus. In one case (N2)x is a uracil and x is 0. In one case (N2)x is a uracil and x is 1. In 15 an instance (N2)x is a uracil and x is 2. In one case (N2)x is a uracil and x is 3. In an instance, (N₂)_x is a uracil and x is 4. In one case (N₂)_x is a uracil and x is 5. In one case, (N₃)_x is a guanine and x is 0. In one case, (N₃)_x is a guanine and x is 1. In one case, (N₄)_x is a cytosine and x is 0. In one case, (N₄)_x is a cytosine and x is 20 1. In one case (N5)x is a uracil and x is 0. In one case (N5)x is a uracil and x is 1. In one case (N5)x is a uracil and x is 2. In one case (N5)x is a uracil and x is 3. In one case, (N₅)_x is a uracil and x is 4. In one case (N₅)_x is a uracil and x is 5. In one case, N6 is a uracil. In one case, N6 is a cytosine. 25 In one case, N7 is a uracil. In one case, N7 is a guanine. In one case, N₈ is an adenine and x is 0. In one case, N₈ is an adenine and x is 1. In one case, N₈ is a guanine and x is 0. In one case, N₈ is a guanine and x is 1. In a different instance, the 5′ UTR comprises a variant of SEQ ID NO: 64. In one case, the variant of SEQ ID NO: 64 comprises a sequence with at least 58%, 60%, 70%, 78 Attorney Docket No.: 45817-0177WO1 / MTX980.20 80%, 85%, 90%, 95%, 96%, 97%, 98%, or 99% identity to SEQ ID NO: 64. In another case, the variant of SEQ ID NO: 64 comprises a sequence with at least 58% identity to SEQ ID NO: 64. In another case, the variant of SEQ ID NO: 64 comprises a sequence with at least 60% identity to SEQ ID NO: 64. In another case, the variant of SEQ ID NO: 5 64 comprises a sequence with at least 70% identity to SEQ ID NO: 64. In another case, the variant of SEQ ID NO: 64 comprises a sequence with at least 80% identity to SEQ ID NO: 64. In another case, the variant of SEQ ID NO: 64 comprises a sequence with at least 90% identity to SEQ ID NO: 64. In another case, the variant of SEQ ID NO: 64 comprises a sequence with at least 95% identity to SEQ ID NO: 64. In another case, the 10 variant of SEQ ID NO: 64 comprises a sequence with at least 96% identity to SEQ ID NO: 64. In another case, the variant of SEQ ID NO: 64 comprises a sequence with at least 97% identity to SEQ ID NO: 64. In another case, the variant of SEQ ID NO: 64 comprises a sequence with at least 98% identity to SEQ ID NO: 64. In another case, the variant of SEQ ID NO: 64 comprises a sequence with at least 99% identity to SEQ ID 15 NO: 64. In another case, the variant of SEQ ID NO: 64 comprises a uridine content of at least 5%, 10%, 20%, 30%, 40%, 58%, 60%, 70%, or 80%. In another case, the variant of SEQ ID NO: 64 comprises a uridine content of at least 5%. In another case, the variant of SEQ ID NO: 64 comprises a uridine content of at least 10%. In another case, the variant of SEQ 20 ID NO: 64 comprises a uridine content of at least 20%. In another case, the variant of SEQ ID NO: 64 comprises a uridine content of at least 30%. In another case, the variant of SEQ ID NO: 64 comprises a uridine content of at least 40%. In another case, the variant of SEQ ID NO: 64 comprises a uridine content of at least 58%. In another case, the variant of SEQ ID NO: 64 comprises a uridine content of at least 60%. In another 25 case, the variant of SEQ ID NO: 64 comprises a uridine content of at least 70%. In another case, the variant of SEQ ID NO: 64 comprises a uridine content of at least 80%. In some instances, the variant of SEQ ID NO: 64 comprises at least 2, 3, 4, 5, 6 or 7 consecutive uridines (e.g., a polyuridine tract). In one case, the polyuridine tract in the variant of SEQ ID NO: 64 comprises at least 1-7, 2-7, 3-7, 4-7, 5-7, 6-7, 1-6, 1-5, 1-4, 1- 79 Attorney Docket No.: 45817-0177WO1 / MTX980.20 3, 1-2, 2-6, or 3-5 consecutive uridines. In another case, the polyuridine tract in the variant of SEQ ID NO: 64 comprises 4 consecutive uridines. In yet another case, the polyuridine tract in the variant of SEQ ID NO: 64 comprises 5 consecutive uridines. In another instance, the variant of SEQ ID NO: 64 comprises 1, 2, 3, 4, 5, 6, 7, 8, 5 9, 10, 11, 12, 13, 14, or 15 polyuridine tracts. In one case, the variant of SEQ ID NO: 64 comprises 3 polyuridine tracts. In another case, the variant of SEQ ID NO: 64 comprises 4 polyuridine tracts. In another case, the variant of SEQ ID NO: 64 comprises 5 polyuridine tracts. In another case, one or more of the polyuridine tracts are adjacent to a different polyuridine tract. In yet another case, each of, e.g., all, the polyuridine tracts are 10 adjacent to each other, e.g., all of the polyuridine tracts are contiguous. In some instances, one or more of the polyuridine tracts are separated by 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 2, 13, 14, 15, 16, 17, 18.19, 20, 30, 40, 50 or 60 nucleotides. In one case, each of, e.g., all of, the polyuridine tracts are separated by 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 2, 13, 14, 15, 16, 17, 18.19, 20, 30, 40, 50 or 60 nucleotides. 15 In one instance, a first polyuridine tract and a second polyuridine tract are adjacent to each other. In another instance, a subsequent, e.g., third, fourth, fifth, sixth or seventh, eighth, ninth, or tenth, polyuridine tract is separated by 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 2, 13, 14, 15, 16, 17, 18.19, 20, 30, 40, 50 or 60 nucleotides from the first polyuridine tract, the 20 second polyuridine tract, or any one of the subsequent polyuridine tracts. In another instance, a first polyuridine tract is separated by 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 2, 13, 14, 15, 16, 17, 18.19, 20, 30, 40, 50 or 60 nucleotides from a subsequent polyuridine tract, e.g., a second, third, fourth, fifth, sixth or seventh, eighth, ninth, or tenth polyuridine tract. In an instance, one or more of the subsequent polyuridine tracts 25 are adjacent to a different polyuridine tract. In yet another instance, the 5′ UTR comprises a Kozak sequence, e.g., a GCCRCC nucleotide sequence wherein R is an adenine or guanine. In one case, the Kozak sequence is disposed at the 3′ end of the 5′UTR sequence. 80 Attorney Docket No.: 45817-0177WO1 / MTX980.20 In another aspect, the polynucleotide (e.g., mRNA) comprising an open reading frame encoding a GPC3 binding CAR protein of the disclosure and comprising a 5′ UTR sequence disclosed herein is formulated as an LNP. In one instance, the LNP composition comprises: (i) an ionizable lipid, e.g., an amino lipid; (ii) a sterol or other structural lipid; 5 (iii) a non-cationic helper lipid or phospholipid; and (iv) a PEG-lipid. In another aspect, the LNP compositions of the disclosure are used in a method of treating a GPC3 positive cancer or tumor in a subject (e.g., human) in need thereof. In another aspect, an LNP composition comprising a polynucleotide disclosed herein encoding a GPC3 binding CAR protein described herein, can be administered with 10 an additional agent, e.g., as described herein. 3′ UTR sequences 3′UTR sequences have been shown to influence translation, half-life, and subcellular localization of mRNAs (Mayr C., Cold Spring Harb Persp Biol 2019 Oct 15 1;11(10):a034728). Disclosed herein, inter alia, is a polynucleotide, e.g., mRNA, comprising an open reading frame encoding a GPC3 binding CAR protein described herein, which polynucleotide has a 3′ UTR that confers an increased half-life, increased expression and/or increased activity of the polypeptide encoded by said polynucleotide, or of the polynucleotide itself. 20 In one instance, a polynucleotide disclosed herein comprises: (a) a 5′-UTR (e.g., as described herein); (b) a coding region comprising a stop element (e.g., as described herein); and (c) a 3′-UTR (e.g., as provided in Table 8 or a variant or fragment thereof), and LNP compositions comprising the same. In one instance, the polynucleotide comprises a 3′-UTR comprising a sequence provided in Table 8, SEQ ID NO: 10, SEQ 25 ID NO:11, SEQ ID NO:12, or a variant or fragment thereof. In some cases, the 3’UTR includes an IDR sequence. In one instance, the polynucleotide having a 3′ UTR sequence provided in Table 8, SEQ ID NO: 10, SEQ ID NO:11, SEQ ID NO:12, or a variant or fragment thereof, results in an increased half-life of the polynucleotide, e.g., about 1.5-10-fold increase in 81 Attorney Docket No.: 45817-0177WO1 / MTX980.20 half-life of the polynucleotide. In one case, the increase in half-life is about 1.5, 2, 3, 4, 5, 6, 7, 8, 9, or 10-fold, or more. In another case, the increase in half-life is about 1.5-fold or more. In a further case, the increase in half-life is about 2-fold or more. In an another case, the increase in half-life is about 3-fold or more. In yet another case, the increase in 5 half-life is about 4-fold or more. In another case, the increase in half-life is about 5-fold or more. In an another case, the increase in half-life is about 6-fold or more. In a further case, the increase in half-life is about 7-fold or more. In another case, the increase in half- life is about 8-fold. In yet another case, the increase in half-life is about 9-fold or more. In another case, the increase in half-life is about 10-fold or more. 10 In another instance, the polynucleotide having a 3′ UTR sequence provided in Table 8, SEQ ID NO: 10, SEQ ID NO:11, SEQ ID NO:12, or a variant or fragment thereof, results in a polynucleotide with a mean half-life score of greater than 10. In another instance, the polynucleotide having a 3′ UTR sequence provided in Table 8, SEQ ID NO: 10, SEQ ID NO:11, SEQ ID NO:12, or a variant or fragment 15 thereof, results in an increased level and/or activity, e.g., output, of the polypeptide encoded by the polynucleotide. In another instance, the increase is compared to an otherwise similar polynucleotide which does not have a 3′ UTR, has a different 3′ UTR, or does not have a 3′ UTR of Table 8, SEQ ID NO: 10, SEQ ID NO:11, SEQ ID NO:12, or a variant or 20 fragment thereof. In another instance, the polynucleotide comprises a 3′ UTR sequence provided in Table 8, SEQ ID NO: 10, SEQ ID NO:11, SEQ ID NO:12, or a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to a 3′ UTR sequence provided in Table 8, SEQ ID NO: 10, SEQ ID NO:11, SEQ ID NO:12, or a fragment 25 thereof. In one case, the 3′ UTR comprises a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to SEQ ID NO: 87, SEQ ID NO: 88, SEQ ID NO: 89, SEQ ID NO: 90, SEQ ID NO: 91, SEQ ID NO: 92, SEQ ID NO: 93, SEQ ID NO: 94, SEQ ID NO: 95, SEQ ID NO: 96, SEQ ID NO: 97, SEQ ID NO: 98, SEQ ID 82 Attorney Docket No.: 45817-0177WO1 / MTX980.20 NO: 99, SEQ ID NO: 100, SEQ ID NO: 101, SEQ ID NO:102, SEQ ID NO:10, SEQ ID NO:11, or SEQ ID NO:12. In one case, the 3′ UTR comprises the sequence of SEQ ID NO: 87, or a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to SEQ ID 5 NO: 87. In one case, the 3′ UTR comprises the sequence of SEQ ID NO: 88, or a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to SEQ ID NO: 88. In one case, the 3′ UTR comprises the sequence of SEQ ID NO: 89, or a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to SEQ ID NO: 89. In one case, the 3′ UTR comprises the sequence of SEQ ID NO: 90, or 10 a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to SEQ ID NO: 90. In one case, the 3′ UTR comprises the sequence of SEQ ID NO: 91, or a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to SEQ ID NO: 91. In one case, the 3′ UTR comprises the sequence of SEQ ID NO: 92, or a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to 15 SEQ ID NO: 92. In one case, the 3′ UTR comprises the sequence of SEQ ID NO: 93, or a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to SEQ ID NO: 93. In one case, the 3′ UTR comprises the sequence of SEQ ID NO: 94, or a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to SEQ ID NO: 94. In one case, the 3′ UTR comprises the sequence of SEQ ID NO: 95, or a 20 sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to SEQ ID NO: 95. In one case, the 3′ UTR comprises the sequence of SEQ ID NO: 96, or a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to SEQ ID NO: 96. In one case, the 3′ UTR comprises the sequence of SEQ ID NO: 97, or a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to 25 SEQ ID NO: 97. In one case, the 3′ UTR comprises the sequence of SEQ ID NO: 98, or a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to SEQ ID NO: 98. In one case, the 3′ UTR comprises the sequence of SEQ ID NO: 99, or a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to SEQ ID NO: 99. In one case, the 3′ UTR comprises the sequence of SEQ ID NO: 100, or 83 Attorney Docket No.: 45817-0177WO1 / MTX980.20 a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to SEQ ID NO: 100. In one case, the 3′ UTR comprises the sequence of SEQ ID NO: 101, or a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to SEQ ID NO: 101. In one case, the 3′ UTR comprises the sequence of SEQ ID NO: 5 102, or a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to SEQ ID NO: 102. In one case, the 3′ UTR comprises the sequence of SEQ ID NO: 10, or a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to SEQ ID NO: 10. In one case, the 3′ UTR comprises the sequence of SEQ ID NO:11, or a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% 10 or 100% identity to SEQ ID NO:11. In one case, the 3′ UTR comprises the sequence of SEQ ID NO: 12, or a sequence with at least 80%, 85%, 90%, 95%, 96%, 97%, 98%, 99% or 100% identity to SEQ ID NO: 12. Table 8: 3′ UTR sequences SEQ Sequence Sequence A G G C U G G A G 84 Attorney Docket No.: 45817-0177WO1 / MTX980.20 90 B5 UGAUAGUAAGCUGGAGCCUCCUUCCAUCUAGUCACAA AGACUCCUUCGUCCCCAGUUGCCGUCUAGGAUUGGGC G C C G A A G U A G G G U G G U G G G 85 Attorney Docket No.: 45817-0177WO1 / MTX980.20 97 B12 UGAUAAUAGGCUGGAGCCUCGGUGGCCUAGCUUCUUG CCCCUUGGGCCUCCCCCCAGCCCCUCCUCCCCUUCCUG G G G G G G G C C A G C A G C C A 86 Attorney Docket No.: 45817-0177WO1 / MTX980.20 AGGAGCGUACCCCCGUGGUCUUUGAAUAAAGUCUGAG UGGGCGGC C C G G A C C C G G U U G G U U U C A C 87 Attorney Docket No.: 45817-0177WO1 / MTX980.20 UUCCUGCACCCGUACCCCCUCCAUAAAGUAGGAAACA CUACAGUGGUCUUUGAAUAAAGUCUGAGUGGGCGGC C C G C A C A A A A C U C U C C In some instances, the 3’UTR comprises the sequence: UAAAGCUCCCCGGGGCAAACACCAUUGUCACACUCCAGCCUCGGUGGCCUA GCUUCUUGCCCCUUGGGCCCAAACACCAUUGUCACACUCCAUCCCCCCAGC 5 CCCUCCUCCCCUUCCUGCACCCGUACCCCCCAAACACCAUUGUCACACUCCA GUGGUCUUUGAAUAAAGUCUGAGUGGGCGGC (SEQ ID NO:141). 88 Attorney Docket No.: 45817-0177WO1 / MTX980.20 In certain instances, the 3′ UTR comprises a micro RNA (miRNA) binding site, e.g., as described herein, which binds to a miR present in a human cell. In one case, the 3′ UTR comprises a miRNA binding site of SEQ ID NO: 113, SEQ ID NO: 114, SEQ ID NO: 115 or a combination thereof. In another case, the 3′ UTR comprises a plurality of 5 miRNA binding sites, e.g., 2, 3, 4, 5, 6, 7 or 8 miRNA binding sites. In one case, the 3′ UTR comprises 3 miRNA122 binding sites (SEQ ID NO:113). In another case, the 3′ UTR comprises 3 miRNA142 binding sites (SEQ ID NO:114). In some cases, the plurality of miRNA binding sites comprises the same or different miRNA binding sites. miR122 bs = CAAACACCAUUGUCACACUCCA (SEQ ID NO: 113) 10 miR-142-3p bs = UCCAUAAAGUAGGAAACACUACA (SEQ ID NO: 114) miR-126 bs = CGCAUUAUUACUCACGGUACGA (SEQ ID NO: 115) In some instances, disclosed herein is a polynucleotide encoding a polypeptide, wherein the polynucleotide comprises: (a) a 5′-UTR, e.g., as described herein; (b) a coding region comprising a stop element (e.g., as described herein); and (c) a 3′-UTR 15 (e.g., as described herein). In certain instances, an LNP composition comprising a polynucleotide comprising an open reading frame encoding a GPC3 binding CAR protein described herein and comprising a 3′ UTR disclosed herein comprises: (i) an ionizable lipid, e.g., an amino lipid; (ii) a sterol or other structural lipid; (iii) a non-cationic helper lipid or phospholipid; 20 and (iv) a PEG-lipid. In one instance, the LNP compositions of the disclosure are used in a method of treating a GPC3 positive cancer or tumor in a subject (e.g., human) in need thereof. In another instance, an LNP composition comprising a polynucleotide disclosed herein encoding a GPC3 binding CAR protein described herein, can be administered with 25 an additional agent, e.g., as described herein. Regions having a 5′ Cap 89 Attorney Docket No.: 45817-0177WO1 / MTX980.20 The disclosure also includes a polynucleotide that comprises both a 5′ Cap and a polynucleotide of the present disclosure (e.g., a polynucleotide comprising a nucleotide sequence encoding a GPC3 binding CAR protein described herein to be expressed). The 5′ cap structure of a natural mRNA is involved in nuclear export, increasing 5 mRNA stability and binds the mRNA Cap Binding Protein (CBP), which is responsible for mRNA stability in the cell and translation competency through the association of CBP with poly(A) binding protein to form the mature cyclic mRNA species. The cap further assists the removal of 5′ proximal introns during mRNA splicing. Endogenous mRNA molecules can be 5′-end capped generating a 5′-ppp-5′- 10 triphosphate linkage between a terminal guanosine cap residue and the 5′-terminal transcribed sense nucleotide of the mRNA molecule. This 5′-guanylate cap can then be methylated to generate an N7-methyl-guanylate residue. The ribose sugars of the terminal and/or anteterminal transcribed nucleotides of the 5′ end of the mRNA can optionally also be 2′-O-methylated.5′-decapping through hydrolysis and cleavage of the guanylate 15 cap structure can target a nucleic acid molecule, such as an mRNA molecule, for degradation. In some instances, the polynucleotides of the present disclosure (e.g., a polynucleotide comprising a nucleotide sequence encoding a GPC3 binding CAR protein described herein) incorporate a cap moiety. 20 In some instances, polynucleotides of the present disclosure comprise a non- hydrolyzable cap structure preventing decapping and thus increasing mRNA half-life. Because cap structure hydrolysis requires cleavage of 5′-ppp-5′ phosphorodiester linkages, modified nucleotides can be used during the capping reaction. For example, a Vaccinia Capping Enzyme from New England Biolabs (Ipswich, MA) can be used with 25 α-thio-guanosine nucleotides according to the manufacturer's instructions to create a phosphorothioate linkage in the 5′-ppp-5′ cap. Additional modified guanosine nucleotides can be used such as α-methyl-phosphonate and seleno-phosphate nucleotides. Additional modifications include, but are not limited to, 2′-O-methylation of the ribose sugars of 5′-terminal and/or 5′-anteterminal nucleotides of the polynucleotide (as 90 Attorney Docket No.: 45817-0177WO1 / MTX980.20 mentioned above) on the 2′-hydroxyl group of the sugar ring. Multiple distinct 5′-cap structures can be used to generate the 5′-cap of a nucleic acid molecule, such as a polynucleotide that functions as an mRNA molecule. Cap analogs, which herein are also referred to as synthetic cap analogs, chemical caps, chemical cap analogs, or structural or 5 functional cap analogs, differ from natural (i.e., endogenous, wild-type or physiological) 5′-caps in their chemical structure, while retaining cap function. Cap analogs can be chemically (i.e., non-enzymatically) or enzymatically synthesized and/or linked to the polynucleotides of the disclosure. For example, the Anti-Reverse Cap Analog (ARCA) cap contains two guanines 10 linked by a 5′-5′-triphosphate group, wherein one guanine contains an N7 methyl group as well as a 3′-O-methyl group (i.e., N7,3′-O-dimethyl-guanosine-5′-triphosphate-5′- guanosine (m7G-3′mppp-G; which can equivalently be designated 3′ O-Me- m7G(5′)ppp(5′)G). The 3′-O atom of the other, unmodified, guanine becomes linked to the 5′-terminal nucleotide of the capped polynucleotide. The N7- and 3′-O-methlyated 15 guanine provides the terminal moiety of the capped polynucleotide. Another exemplary cap is mCAP, which is similar to ARCA but has a 2′-O- methyl group on guanosine (i.e., N7,2′-O-dimethyl-guanosine-5′-triphosphate-5′- guanosine, m7Gm-ppp-G). Another exemplary cap is m7G-ppp-Gm-A (i.e., N7,guanosine-5′-triphosphate-2′-O- 20 dimethyl-guanosine-adenosine). In some instances, the cap is a dinucleotide cap analog. As a non-limiting example, the dinucleotide cap analog can be modified at different phosphate positions with a boranophosphate group or a phosphoroselenoate group such as the dinucleotide cap analogs described in U.S. Patent No. US 8,519,110, the contents of which are herein 25 incorporated by reference in its entirety. In another instance, the cap is a cap analog is a N7-(4-chlorophenoxyethyl) substituted dinucleotide form of a cap analog known in the art and/or described herein. Non-limiting examples of a N7-(4-chlorophenoxyethyl) substituted dinucleotide form of a cap analog include a N7-(4-chlorophenoxyethyl)-G(5′)ppp(5′)G and a N7-(4- 91 Attorney Docket No.: 45817-0177WO1 / MTX980.20 chlorophenoxyethyl)-m3′-OG(5′)ppp(5′)G cap analog (See, e.g., the various cap analogs and the methods of synthesizing cap analogs described in Kore et al. Bioorganic & Medicinal Chemistry 201321:4570-4574; the contents of which are herein incorporated by reference in its entirety). In another instance, a cap analog of the present disclosure is 5 a 4-chloro/bromophenoxyethyl analog. Polynucleotides of the disclosure can also be capped post-manufacture (whether IVT or chemical synthesis), using enzymes, in order to generate more authentic 5′-cap structures. As used herein, the phrase "more authentic" refers to a feature that closely mirrors or mimics, either structurally or functionally, an endogenous or wild type feature. 10 That is, a "more authentic" feature is better representative of an endogenous, wild-type, natural or physiological cellular function and/or structure as compared to synthetic features or analogs, etc., of the prior art, or which outperforms the corresponding endogenous, wild-type, natural or physiological feature in one or more respects. Non- limiting examples of more authentic 5′cap structures of the present disclosure are those15 that, among other things, have enhanced binding of cap binding proteins, increased half- life, reduced susceptibility to 5′ endonucleases and/or reduced 5′decapping, as compared to synthetic 5′cap structures known in the art (or to a wild-type, natural or physiological 5′cap structure). For example, recombinant Vaccinia Virus Capping Enzyme and recombinant 2′-O-methyltransferase enzyme can create a canonical 5′-5′-triphosphate 20 linkage between the 5′-terminal nucleotide of a polynucleotide and a guanine cap nucleotide wherein the cap guanine contains an N7 methylation and the 5′-terminal nucleotide of the mRNA contains a 2′-O-methyl. Such a structure is termed the Cap1 structure. This cap results in a higher translational-competency and cellular stability and a reduced activation of cellular pro-inflammatory cytokines, as compared, e.g., to other 25 5′cap analog structures known in the art. Cap structures include, but are not limited to, 7mG(5′)ppp(5′)N1pN2p (cap 0), 7mG(5′)ppp(5′)N1mpNp (cap 1), and 7mG(5′)- ppp(5′)N1mpN2mp (cap 2). As a non-limiting example, capping chimeric polynucleotides post-manufacture can be more efficient as nearly 100% of the chimeric polynucleotides can be capped. This 92 Attorney Docket No.: 45817-0177WO1 / MTX980.20 is in contrast to ~80% when a cap analog is linked to a chimeric polynucleotide in the course of an in vitro transcription reaction. According to the present disclosure, 5′ terminal caps can include endogenous caps or cap analogs. A 5′ terminal cap can comprise a guanine analog. Useful guanine analogs 5 include, but are not limited to, inosine, N1-methyl-guanosine, 2′fluoro-guanosine, 7- deaza-guanosine, 8-oxo-guanosine, 2-amino-guanosine, LNA-guanosine, and 2-azido- guanosine. Also provided herein are exemplary caps including those that can be used in co- transcriptional capping methods for ribonucleic acid (RNA) synthesis, using RNA 10 polymerase, e.g., wild type RNA polymerase or variants thereof, e.g., such as those variants described herein. In one instance, caps can be added when RNA is produced in a “one-pot” reaction, without the need for a separate capping reaction. Thus, the methods, in some instances, comprise reacting a polynucleotide template with an RNA polymerase variant, nucleoside triphosphates, and a cap analog under in vitro transcription reaction 15 conditions to produce RNA transcript. As used here the term “cap” includes the inverted G nucleotide and can comprise one or more additional nucleotides 3′ of the inverted G nucleotide, e.g., 1, 2, 3, or more nucleotides 3′ of the inverted G nucleotide and 5′ to the 5′ UTR, e.g., a 5′ UTR described herein. 20 Exemplary caps comprise a sequence of GG, GA, or GGA, wherein the underlined, italicized G is an in inverted G nucleotide followed by a 5′-5′-triphosphate group. In one instance, a cap comprises a compound of formula (I) 93 Attorney Docket No.: 45817-0177WO1 / MTX980.20 er, 5 ring B₂ and ring B₃ each independently is a nucleobase or a modified nucleobase; X₂ is O, S(O)_p, NR₂₄ or CR₂₅R₂₆ in which p is 0, 1, or 2; Y0 is O or CR6R7; Y₁ is O, S(O)_n, CR₆R₇, or NR₈, in which n is 0, 1 , or 2; 10 each --- is a single bond or absent, wherein when each --- is a single bond, Yi is O, S(O)n, CR6R7, or NR8; and when each --- is absent, Y1 is void; Y2 is (OP(O)R4)m in which m is 0, 1, or 2, or -O-(CR40R41)u-Q0-(CR42R43)v-, in which Q₀ is a bond, O, S(O)_r, NR₄₄, or CR₄₅R₄₆, r is 0, 1 , or 2, and each of u and v independently is 1, 2, 3 or 4; 15 each R2 and R2′ independently is halo, LNA, or OR3; each R₃ independently is H, C1-C6 alkyl, C2-C6 alkenyl, or C2-C6 alkynyl and R3, when being C1-C6 alkyl, C2-C6 alkenyl, or C2-C6 alkynyl, is optionally substituted with one or more of halo, OH and C1-C6 alkoxyl that is optionally substituted with one or more OH or OC(O)-C1-C6 alkyl; 94 Attorney Docket No.: 45817-0177WO1 / MTX980.20 each R4 and R4′ independently is H, halo, C1-C6 alkyl, OH, SH, SeH, or BH3-; each of R6, R7, and R8, independently, is -Q1-T1, in which Q1 is a bond or C1-C3 alkyl linker optionally substituted with one or more of halo, cyano, OH and C1-C6 alkoxy, and T1 is H, halo, OH, COOH, cyano, or Rs1, in which Rs1 is C1-C3 alkyl, C2- 5 C6 alkenyl, C2-C6 alkynyl, C1- C6 alkoxyl, C(O)O-C1-C6 alkyl, C3-C8 cycloalkyl, C6- C10 aryl, NR₃₁R₃₂, (NR₃₁R₃₂R₃₃)+, 4 to 12- membered heterocycloalkyl, or 5- or 6- membered heteroaryl, and Rs1 is optionally substituted with one or more substituents selected from the group consisting of halo, OH, oxo, C1-C6 alkyl, COOH, C(O)O-C1- C6 alkyl, cyano, C1-C6 alkoxyl, NR₃₁R₃₂, (NR₃₁R₃₂R₃₃)+, C3-C8 cycloalkyl, C6- 10 C10 aryl, 4 to 12-membered heterocycloalkyl, and 5- or 6-membered heteroaryl; each of R10, R11, R12, R13, R14, and R15, independently, is -Q2-T2, in which Q2 is a bond or C1-C3 alkyl linker optionally substituted with one or more of halo, cyano, OH and C1-C6 alkoxy, and T₂ is H, halo, OH, NH₂, cyano, NO₂, N₃, Rs₂, or ORs₂, in which Rs2 is C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C3-C8 cycloalkyl, C6-C10 aryl, 15 NHC(O)-C1-C6 alkyl, NR31R32, (NR31R32R33)+, 4 to 12-membered heterocycloalkyl, or 5- or 6-membered heteroaryl, and Rs2 is optionally substituted with one or more substituents selected from the group consisting of halo, OH, oxo, C1-C6 alkyl, COOH, C(O)O-C1-C6 alkyl, cyano, C1 - C6 alkoxyl, NR31R32, (NR31R32R33)+, C3- C8 cycloalkyl, C6-C10 aryl, 4 to 12-membered heterocycloalkyl, and 5- or 6- membered 20 heteroaryl; or alternatively R₁₂ together with R₁₄ is oxo, or R₁₃ together with R₁₅ is oxo, each of R20, R21, R22, and R23 independently is -Q3-T3, in which Q3 is a bond or C1-C3 alkyl linker optionally substituted with one or more of halo, cyano, OH and C1-C6 alkoxy, and T₃ is H, halo, OH, NH₂, cyano, NO₂, N₃, R_S3, or OR_S3, in which RS3 is C1- C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C3-C8 cycloalkyl, C6-C10 aryl, NHC(O)-C1- 25 C6 alkyl, mono-C1-C6 alkylamino, di-C1-C6 alkylamino, 4 to 12-membered heterocycloalkyl, or 5- or 6-membered heteroaryl, and Rs3 is optionally substituted with one or more substituents selected from the group consisting of halo, OH, oxo, C1-C6 alkyl, COOH, C(O)O-C1-C6 alkyl, cyano, C1-C6 alkoxyl, amino, mono-C1-C6 95 Attorney Docket No.: 45817-0177WO1 / MTX980.20 alkylamino, di-C1-C6 alkylamino, C3-C8 cycloalkyl, C6-C10 aryl, 4 to 12-membered heterocycloalkyl, and 5- or 6-membered heteroaryl; each of R₂₄, R₂₅, and R₂₆ independently is H or C1-C6 alkyl; each of R27 and R28 independently is H or OR29; or R27 and R28 together form O- 5 R30-O; each R29 independently is H, C1-C6 alkyl, C2-C6 alkenyl, or C2-C6 alkynyl and R29, when being C1-C6 alkyl, C2-C6 alkenyl, or C2-C6 alkynyl, is optionally substituted with one or more of halo, OH and C1-C6 alkoxyl that is optionally substituted with one or more OH or OC(O)-C1-C6 alkyl; R₃₀ is C1-C6 alkylene optionally substituted with one or more of halo, OH and 10 C1-C6 alkoxyl; each of R31, R32, and R33, independently is H, C1-C6 alkyl, C3-C8 cycloalkyl, C6-C10 aryl, 4 to 12-membered heterocycloalkyl, or 5- or 6-membered heteroaryl; each of R₄₀, R₄₁, R₄₂, and R₄₃ independently is H, halo, OH, cyano, N3, OP(O)R47R48, or C1-C6 alkyl optionally substituted with one or more OP(O)R47R48, or 15 one R41 and one R43, together with the carbon atoms to which they are attached and Q0, form C4-C10 cycloalkyl, 4- to 14-membered heterocycloalkyl, C6-C10 aryl, or 5- to 14- membered heteroaryl, and each of the cycloalkyl, heterocycloalkyl, phenyl, or 5- to 6- membered heteroaryl is optionally substituted with one or more of OH, halo, cyano, N3, oxo, OP(O)R₄₇R₄₈, C1-C6 alkyl, C1-C6 haloalkyl, COOH, C(O)O-C1-C6 alkyl, C1-C6 20 alkoxyl, C1-C6 haloalkoxyl, amino, mono-C1-C6 alkylamino, and di-C1-C6 alkylamino; R44 is H, C1-C6 alkyl, or an amine protecting group; each of R45 and R46 independently is H, OP(O)R47R48, or C1-C6 alkyl optionally substituted with one or more OP(O)R₄₇R₄₈, and each of R47 and R48, independently is H, halo, C1-C6 alkyl, OH, SH, SeH, or BH3 25 . It should be understood that a cap analog, as provided herein, may include any of the cap analogs described in international publication WO 2017/066797, published on 20 April 2017, incorporated by reference herein in its entirety. 96 Attorney Docket No.: 45817-0177WO1 / MTX980.20 In some instances, the B2 middle position can be a non-ribose molecule, such as arabinose. In some instances, R₂ is ethyl-based. Thus, in some instances, a cap comprises the following structure: II) In other instances, a cap comprises the following structure: III) Attorney Docket No.: 45817-0177WO1 / MTX980.20 In yet other instances, a cap comprises the following structure: V) In still other instances, a cap comprises the following structure: 5 V) In some instances, R is an alkyl (e.g., C1-C6 alkyl). In some instances, R is a methyl group (e.g., C1 alkyl). In some instances, R is an ethyl group (e.g., C2 alkyl). In some instances, a cap comprises a sequence selected from the following 10 sequences: GAA, GAC, GAG, GAU, GCA, GCC, GCG, GCU, GGA , GGC, GGG, 98 Attorney Docket No.: 45817-0177WO1 / MTX980.20 GGU, GUA, GUC, GUG, and GUU. In some instances, a cap comprises GAA. In some instances, a cap comprises GAC. In some instances, a cap comprises GAG. In some instances, a cap comprises GAU. In some instances, a cap comprises GCA. In some instances, a cap comprises GCC. In some instances, a cap comprises GCG. In some 5 instances, a cap comprises GCU. In some instances, a cap comprises GGA. In some instances, a cap comprises GGC. In some instances, a cap comprises GGG. In some instances, a cap comprises GGU. In some instances, a cap comprises GUA. In some instances, a cap comprises GUC. In some instances, a cap comprises GUG. In some instances, a cap comprises GUU. 10 In some instances, a cap comprises a sequence selected from the following sequences: m7GpppApA, m7GpppApC, m7GpppApG, m7GpppApU, m7GpppCpA, m7GpppCpC, m7GpppCpG, m7GpppCpU, m7GpppGpA, m7GpppGpC, m7GpppGpG, m7GpppGpU, m7GpppUpA, m7GpppUpC, m7GpppUpG, and m7GpppUpU. In some instances, a cap comprises m7GpppApA. In some instances, a cap 15 comprises m7GpppApC. In some instances, a cap comprises m7GpppApG. In some instances, a cap comprises m7GpppApU. In some instances, a cap comprises m7GpppCpA. In some instances, a cap comprises m7GpppCpC. In some instances, a cap comprises m7GpppCpG. In some instances, a cap comprises m7GpppCpU. In some instances, a cap comprises m7GpppGpA. In some instances, a cap comprises 20 m7GpppGpC. In some instances, a cap comprises m7GpppGpG. In some instances, a cap comprises m7GpppGpU. In some instances, a cap comprises m7GpppUpA. In some instances, a cap comprises m7GpppUpC. In some instances, a cap comprises m7GpppUpG. In some instances, a cap comprises m7GpppUpU. A cap, in some instances, comprises a sequence selected from the following 25 sequences: m7G3^OMepppApA, m7G3^OMepppApC, m7G3^OMepppApG, m7G3^OMepppApU, m7G3^OMepppCpA, m7G3^OMepppCpC, m7G3^OMepppCpG, m7G3^OMepppCpU, m7G3^OMepppGpA, m7G3^OMepppGpC, m7G3^OMepppGpG, m7G3^OMepppGpU, m7G3^OMepppUpA, m7G3^OMepppUpC, m7G3^OMepppUpG, and m7G3^OMepppUpU. 99 Attorney Docket No.: 45817-0177WO1 / MTX980.20 In some instances, a cap comprises m7G3^OMepppApA. In some instances, a cap comprises m7G3^OMepppApC. In some instances, a cap comprises m7G3^OMepppApG. In some instances, a cap comprises m7G3^OMepppApU. In some instances, a cap comprises m7G3^OMepppCpA. In some instances, a cap comprises m7G3^OMepppCpC. 5 In some instances, a cap comprises m7G3^OMepppCpG. In some instances, a cap comprises m7G3^OMepppCpU. In some instances, a cap comprises m7G3^OMepppGpA. In some instances, a cap comprises m7G3^OMepppGpC. In some instances, a cap comprises m7G3^OMepppGpG. In some instances, a cap comprises m7G3^OMepppGpU. In some instances, a cap comprises m7G3^OMepppUpA. In some instances, a cap 10 comprises m7G3^OMepppUpC. In some instances, a cap comprises m7G3^OMepppUpG. In some instances, a cap comprises m7G3^OMepppUpU. A cap, in other instances, comprises a sequence selected from the following sequences: m7G3^OMepppA2^OMepA, m7G3^OMepppA2^OMepC, m7G3^OMepppA2^OMepG, m7G3^OMepppA2^OMepU, m7G3^OMepppC2^OMepA, 15 m7G3^OMepppC2^OMepC, m7G3^OMepppC2^OMepG, m7G3^OMepppC2^OMepU, m7G3^OMepppG2^OMepA, m7G3^OMepppG2^OMepC, m7G3^OMepppG2^OMepG, m7G3^OMepppG2^OMepU, m7G3^OMepppU2^OMepA, m7G3^OMepppU2^OMepC, m7G3^OMepppU2^OMepG, and m7G3^OMepppU2^OMepU. In some instances, a cap comprises m⁷G3^OMepppA_2^OMepA. In some instances, a 20 cap comprises m⁷G3^OMepppA_2^OMepC. In some instances, a cap comprises m⁷G3^OMepppA_2^OMepG. In some instances, a cap comprises m⁷G3^OMepppA_2^OMepU. In some instances, a cap comprises m⁷G3^OMepppC_2^OMepA. In some instances, a cap comprises m⁷G_3^OMepppC2^_OMepC. In some instances, a cap comprises m⁷G3_^OMepppC2_^OMepG. In some instances, a cap comprises m⁷G3^OMepppC2^OMepU. In 25 some instances, a cap comprises m⁷G3^OMepppG2^OMepA. In some instances, a cap comprises m⁷G3^OMepppG2_^OMepC. In some instances, a cap comprises m⁷G3^OMepppG2^OMepG. In some instances, a cap comprises m⁷G3^OMepppG2^OMepU. In some instances, a cap comprises m⁷G3^OMepppU2^OMepA. In some instances, a cap 100 Attorney Docket No.: 45817-0177WO1 / MTX980.20 comprises m⁷G3^OMepppU2^OMepC. In some instances, a cap comprises m⁷G3^OMepppU2^OMepG. In some instances, a cap comprises m⁷G3^OMepppU2^OMepU. A cap, in still other instances, comprises a sequence selected from the following sequences: m⁷GpppA2^_OMepA, m⁷GpppA2^_OMepC, m⁷GpppA2^_OMepG, m⁷GpppA2^_OMepU, 5 m⁷GpppC2^OMepA, m⁷GpppC2^OMepC, m⁷GpppC2^OMepG, m⁷GpppC2^OMepU, m⁷GpppG2^OMepA, m⁷GpppG2^OMepC, m⁷GpppG2^OMepG, m⁷GpppG2^OMepU, m⁷GpppU2^OMepA, m⁷GpppU2^OMepC, m⁷GpppU2^OMepG, and m⁷GpppU2^OMepU. In some instances, a cap comprises m7GpppA2^OMepA. In some instances, a cap comprises m⁷GpppA2^OMepC. In some instances, a cap comprises m⁷GpppA2^OMepG. In 10 some instances, a cap comprises m⁷GpppA2^OMepU. In some instances, a cap comprises m⁷GpppC2^OMepA. In some instances, a cap comprises m⁷GpppC2^OMepC. In some instances, a cap comprises m⁷GpppC2^OMepG. In some instances, a trinucleotide cap comprises m⁷GpppC2^OMepU. In some instances, a cap comprises m7GpppG2^OMepA. In some instances, a cap comprises m⁷GpppG_2^OMepC. In some instances, a cap comprises 15 m⁷GpppG₂^_OMepG. In some instances, a cap comprises m⁷GpppG₂^_OMepU. In some instances, a cap comprises m⁷GpppU₂^_OMepA. In some instances, a cap comprises m⁷GpppU_2^OMepC. In some instances, a cap comprises m⁷GpppU₂^_OMepG. In some instances, a cap comprises m⁷GpppU₂^_OMepU. In some instances, a cap comprises m⁷Gpppm6A2′_OmepG. In some instances, a 20 cap comprises m⁷Gpppe6A2′_OmepG. In some instances, a cap comprises GAG. In some instances, a cap comprises GCG. In some instances, a cap comprises GUG. In some instances, a cap comprises GGG. In some instances, a cap comprises any one of the following structures: 101 Attorney Docket No.: 45817-0177WO1 / MTX980.20 ; or ). In some instances, the cap comprises m⁷GpppN1N2N3, where N1, N2, and N3 are optional (i.e., can be absent or one or more can be present) and are independently a natural, a modified, or an unnatural nucleoside base. In some instances, ^m7G is further 5 methylated, e.g., at the 3′ position. In some instances, the ^m7G comprises an O-methyl at the 3′ position. In some instances N1, N2, and N3 if present, optionally, are independently an adenine, a uracil, a guanidine, a thymine, or a cytosine. In some instances, one or more (or all) of N₁, N₂, and N₃, if present, are methylated, e.g., at the 2′ position. In some 102 Attorney Docket No.: 45817-0177WO1 / MTX980.20 instances, one or more (or all) of N1, N2, and N3, if present have an O-methyl at the 2′ position. In some instances, the cap comprises the following structure: X) 5 w unnatural nucleoside based; and R1, R2, R3, and R4 are independently OH or O-methyl. In some instances, R₃ is O-methyl and R4 is OH. In some instances, R₃ and R₄ are O-methyl. In some instances, R4 is O-methyl. In some instances, R1 is OH, R2 is OH, R3 is O-methyl, and R4 is OH. In some instances, R1 is OH, R2 is OH, R3 is O-methyl, and R4 is O- 10 methyl. In some instances, at least one of R₁ and R₂ is O-methyl, R₃ is O-methyl, and R₄ is OH. In some instances, at least one of R₁ and R₂ is O-methyl, R₃ is O-methyl, and R₄ is O-methyl. In some instances, B1, B2, and B3 are natural nucleoside bases. In some instances, at least one of B₁, B₂, and B₃ is a modified or unnatural base. In some instances, at least 15 one of B1, B2, and B3 is N6-methyladenine. In some instances, B1 is adenine, cytosine, thymine, or uracil. In some instances, B1 is adenine, B2 is uracil, and B3 is adenine. In some instances, R₁ and R₂ are OH, R₃ and R₄ are O-methyl, B₁ is adenine, B₂ is uracil, and B3 is adenine. In some instances, the cap comprises a sequence selected from the following 20 sequences: GAAA, GACA, GAGA, GAUA, GCAA, GCCA, GCGA, GCUA, GGAA, GGCA, GGGA, GGUA, GUCA, and GUUA. In some instances, the cap comprises a 103 Attorney Docket No.: 45817-0177WO1 / MTX980.20 sequence selected from the following sequences: GAAG, GACG, GAGG, GAUG, GCAG, GCCG, GCGG, GCUG, GGAG, GGCG, GGGG, GGUG, GUCG, GUGG, and GUUG. In some instances, the cap comprises a sequence selected from the following sequences: GAAU, GACU, GAGU, GAUU, GCAU, GCCU, GCGU, GCUU, GGAU, 5 GGCU, GGGU, GGUU, GUAU, GUCU, GUGU, and GUUU. In some instances, the cap comprises a sequence selected from the following sequences: GAAC, GACC, GAGC, GAUC, GCAC, GCCC, GCGC, GCUC, GGAC, GGCC, GGGC, GGUC, GUAC, GUCC, GUGC, and GUUC. A cap, in some instances, comprises a sequence selected from the following 10 sequences: m7G3^OMepppApApN, m7G3^OMepppApCpN, m7G3^OMepppApGpN, m7G3^OMepppApUpN, m7G3^OMepppCpApN, m7G3^OMepppCpCpN, m7G3^OMepppCpGpN, m7G3^OMepppCpUpN, m7G3^OMepppGpApN, m7G3^OMepppGpCpN, m7G3^OMepppGpGpN, m7G3^OMepppGpUpN, m7G3^OMepppUpApN, m7G3^OMepppUpCpN, m7G3^OMepppUpGpN, and 15 m7G3^OMepppUpUpN, where N is a natural, a modified, or an unnatural nucleoside base. A cap, in other instances, comprises a sequence selected from the following sequences: m7G3^OMepppA2^OMepApN, m7G3^OMepppA2^OMepCpN, m7G3^OMepppA2^OMepGpN, m7G3^OMepppA2^OMepUpN, 20 m7G3^OMepppC2^OMepApN, m7G3^OMepppC2^OMepCpN, m7G3^OMepppC2^OMepGpN, m7G3^OMepppC2^OMepUpN, m7G3^OMepppG2^OMepApN, m7G3^OMepppG2^OMepCpN, m7G3^OMepppG2^OMepGpN, m7G3^OMepppG2^OMepUpN, m7G3^OMepppU2^OMepApN, m7G3^OMepppU2^OMepCpN, 25 m7G3^OMepppU2^OMepGpN, and m7G3^OMepppU2^OMepUpN, where N is a natural, a modified, or an unnatural nucleoside base. A cap, in still other instances, comprises a sequence selected from the following sequences: m7GpppA2^OMepApN, m7GpppA2^OMepCpN, m7GpppA2^OMepGpN, 104 Attorney Docket No.: 45817-0177WO1 / MTX980.20 m⁷GpppA2^OMepUpN, m7GpppC2^OMepApN, m7GpppC2^OMepCpN, m7GpppC2^OMepGpN, m7GpppC2^OMepUpN, m7GpppG2^OMepApN, m7GpppG2^OMepCpN, m7GpppG2^OMepGpN, m7GpppG2^OMepUpN, m7GpppU2^OMepApN, m7GpppU2^OMepCpN, m7GpppU2^OMepGpN, and 5 m7GpppU2^OMepUpN, where N is a natural, a modified, or an unnatural nucleoside base. A cap, in other instances, comprises a sequence selected from the following sequences: m7G3^OMepppA2^OMepA2^OMepN, m7G3^OMepppA2^OMepC2^OMepN, m7G3^OMepppA2^OMepG2^OMepN, m7G3^OMepppA2^OMepU2^OMepN, 10 m7G3^OMepppC2^OMepA2^OMepN, m7G3^OMepppC2^OMepC2^OMepN, m7G3^OMepppC2^OMepG2^OMepN, m7G3^OMepppC2^OMepU2^OMepN, m7G3^OMepppG2^OMepA2^OMepN, m7G3^OMepppG2^OMepC2^OMepN, m7G3^OMepppG2^OMepG2^OMepN, m7G3^OMepppG2^OMepU2^OMepN, m7G3^OMepppU2^OMepA2^OMepN, m7G3^OMepppU2^OMepC2^OMepN, 15 m7G3^OMepppU2^OMepG2^OMepN, and m7G3^OMepppU2^OMepU2^OMepN, where N is a natural, a modified, or an unnatural nucleoside base. A cap, in still other instances, comprises a sequence selected from the following sequences: m7GpppA2^OMepA2^OMepN, m7GpppA2^OMepC2^OMepN, m7GpppA2^OMepG2^OMepN, m7GpppA2^OMepU2^OMepN, 20 m7GpppC2^OMepA2^OMepN, m7GpppC2^OMepC2^OMepN, m7GpppC2^OMepG2^OMepN, m7GpppC2^OMepU2^OMepN, m7GpppG2^OMepA2^OMepN, m7GpppG2^OMepC2^OMepN, m7GpppG2^OMepG2^OMepN, m7GpppG2^OMepU2^OMepN, m7GpppU2^OMepA2^OMepN, m7GpppU2^OMepC2^OMepN, 25 m7GpppU2^OMepG2^OMepN, and m7GpppU2^OMepU2^OMepN, where N is a natural, a modified, or an unnatural nucleoside base. In some instances, a cap comprises GGAG. In some instances, a cap comprises the following structure: 105 Attorney Docket No.: 45817-0177WO1 / MTX980.20 X). In one case, the terminal cap is m7G-ppp-Gm. In another case, terminal cap is m7G-ppp-Gm-A. 5 Poly A Tails In some instances, the polynucleotides of the present disclosure (e.g., a polynucleotide comprising a nucleotide sequence encoding GPC3 binding CAR protein described herein further comprise a poly A tail. In further instances, terminal groups on 10 the poly A tail can be incorporated for stabilization. In other instances, a poly A tail comprises des-3′ hydroxyl tails. During RNA processing, a long chain of adenine nucleotides (poly A tail) can be added to a polynucleotide such as an mRNA molecule in order to increase stability. Immediately after transcription, the 3′ end of the transcript can be cleaved to free a 3′ 15 hydroxyl. Then poly A polymerase adds a chain of adenine nucleotides to the RNA. The process, called polyadenylation, adds a poly A tail that can be between, for example, approximately 80 to approximately 250 residues long, including approximately 80, 90, 100, 110, 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220, 230, 240 or 250 residues long. In one instance, the poly A tail is 100 nucleotides in length (SEQ ID NO:117). In 20 some instances, the poly A tail can include an IDR sequence(s). 106 Attorney Docket No.: 45817-0177WO1 / MTX980.20 Poly A tails can also be added after the construct is exported from the nucleus. According to the present disclosure, terminal groups on the poly A tail can be incorporated for stabilization. Polynucleotides of the present disclosure can include des-3′ hydroxyl tails. They can also include structural moieties or 2′-Omethyl modifications as 5 taught by Junjie Li, et al. (Current Biology, Vol.15, 1501–1507, August 23, 2005, the contents of which are incorporated herein by reference in its entirety). The polynucleotides of the present disclosure can be designed to encode transcripts with alternative poly A tail structures including histone mRNA. According to Norbury, "Terminal uridylation has also been detected on human replication-dependent 10 histone mRNAs. The turnover of these mRNAs is thought to be important for the prevention of potentially toxic histone accumulation following the completion or inhibition of chromosomal DNA replication. These mRNAs are distinguished by their lack of a 3ʹ poly(A) tail, the function of which is instead assumed by a stable stem–loop structure and its cognate stem–loop binding protein (SLBP); the latter carries out the 15 same functions as those of PABP on polyadenylated mRNAs" (Norbury, "Cytoplasmic RNA: a case of the tail wagging the dog," Nature Reviews Molecular Cell Biology; AOP, published online 29 August 2013; doi:10.1038/nrm3645) the contents of which are incorporated herein by reference in its entirety. Unique poly A tail lengths provide certain advantages to the polynucleotides of 20 the present disclosure. Generally, the length of a poly A tail, when present, is greater than 30 nucleotides in length. In another instance, the poly A tail is greater than 35 nucleotides in length (e.g., at least or greater than about 35, 40, 45, 50, 55, 60, 70, 80, 90, 100, 120, 140, 160, 180, 200, 250, 300, 350, 400, 450, 500, 600, 700, 800, 900, 1,000, 1,100, 1,200, 1,300, 1,400, 1,500, 1,600, 1,700, 1,800, 1,900, 2,000, 2,500, and 3,000 nucleotides). 25 In some instances, the polynucleotide or region thereof includes from about 30 to about 3,000 nucleotides (e.g., from 30 to 50, from 30 to 100, from 30 to 250, from 30 to 500, from 30 to 750, from 30 to 1,000, from 30 to 1,500, from 30 to 2,000, from 30 to 2,500, from 50 to 100, from 50 to 250, from 50 to 500, from 50 to 750, from 50 to 1,000, from 50 to 1,500, from 50 to 2,000, from 50 to 2,500, from 50 to 3,000, from 100 to 500, 107 Attorney Docket No.: 45817-0177WO1 / MTX980.20 from 100 to 750, from 100 to 1,000, from 100 to 1,500, from 100 to 2,000, from 100 to 2,500, from 100 to 3,000, from 500 to 750, from 500 to 1,000, from 500 to 1,500, from 500 to 2,000, from 500 to 2,500, from 500 to 3,000, from 1,000 to 1,500, from 1,000 to 2,000, from 1,000 to 2,500, from 1,000 to 3,000, from 1,500 to 2,000, from 1,500 to 5 2,500, from 1,500 to 3,000, from 2,000 to 3,000, from 2,000 to 2,500, and from 2,500 to 3,000). In some instances, the poly A tail is designed relative to the length of the overall polynucleotide or the length of a particular region of the polynucleotide. This design can be based on the length of a coding region, the length of a particular feature or region or 10 based on the length of the ultimate product expressed from the polynucleotides. In this context, the poly A tail can be 10, 20, 30, 40, 50, 60, 70, 80, 90, or 100% greater in length than the polynucleotide or feature thereof. The poly A tail can also be designed as a fraction of the polynucleotides to which it belongs. In this context, the poly A tail can be 10, 20, 30, 40, 50, 60, 70, 80, or 90% or more of the total length of the 15 construct, a construct region or the total length of the construct minus the poly A tail. Further, engineered binding sites and conjugation of polynucleotides for Poly A binding protein can enhance expression. Additionally, multiple distinct polynucleotides can be linked together via the PABP (Poly A binding protein) through the 3′-end using modified nucleotides at the 3′- 20 terminus of the poly A tail. Transfection experiments can be conducted in relevant cell lines at and protein production can be assayed by ELISA at 12hr, 24hr, 48hr, 72hr and day 7 post-transfection. In some instances, the polynucleotides of the present disclosure are designed to include a poly A-G Quartet region. The G-quartet is a cyclic hydrogen bonded array of four 25 guanine nucleotides that can be formed by G-rich sequences in both DNA and RNA. In this instance, the G-quartet is incorporated at the end of the poly A tail. The resultant polynucleotide is assayed for stability, protein production and other parameters including half-life at various time points. It has been discovered that the poly A-G quartet results in 108 Attorney Docket No.: 45817-0177WO1 / MTX980.20 protein production from an mRNA equivalent to at least 75% of that seen using a poly A tail of 120 nucleotides alone (SEQ ID NO:118). In some instances, the poly A tail comprises an alternative nucleoside, e.g., inverted thymidine. Poly A tails comprising an alternative nucleoside, e.g., inverted 5 thymidine, may be generated as described herein. For instance, mRNA constructs may be modified by ligation to stabilize the poly(A) tail. Ligation may be performed using 0.5-1.5 mg/mL mRNA (5′ Cap1, 3′ A100), 50 mM Tris-HCl pH 7.5, 10 mM MgCl₂, 1 mM TCEP, 1000 units/mL T4 RNA Ligase 1, 1 mM ATP, 20% w/v polyethylene glycol 8000, and 5:1 molar ratio of modifying oligo to mRNA. Modifying oligo has a sequence 10 of 5′-phosphate-AAAAAAAAAAAAAAAAAAAA-(inverted deoxythymidine (idT) (SEQ ID NO:119)) (see below). Ligation reactions are mixed and incubated at room temperature (~22°C) for, e.g., 4 hours. Stable tail mRNA are purified by, e.g., dT purification, reverse phase purification, hydroxyapatite purification, ultrafiltration into water, and sterile filtration. The resulting stable tail-containing mRNAs contain the15 following structure at the 3′end, starting with the poly A region: A100- UCUAGAAAAAAAAAAAAAAAAAAAA-inverted deoxythymidine (SEQ ID NO:13). Modifying oligo to stabilize tail (5′-phosphate-AAAAAAAAAAAAAAAAAAAA- (inverted deoxythymidine)(SEQ ID NO:119)): 109 Attorney Docket No.: 45817-0177WO1 / MTX980.20 In some instances, the poly A tail comprises A100-UCUAG-A20-inverted deoxy- thymidine (SEQ ID NO:13). In some instances, the poly A tail consists of A100- UCUAG-A20-inverted deoxy-thymidine (SEQ ID NO:13). 5 Start codon region The disclosure also includes a polynucleotide that comprises both a start codon region and the polynucleotide described herein (e.g., a polynucleotide comprising a nucleotide sequence encoding a GPC3 binding CAR protein described herein. In some cases, the polynucleotides of the present disclosure can have regions that are analogous to 10 or function like a start codon region. In some cases, the translation of a polynucleotide can initiate on a codon that is not the start codon AUG. Translation of the polynucleotide can initiate on an alternative start codon such as, but not limited to, ACG, AGG, AAG, CTG/CUG, GTG/GUG, ATA/AUA, ATT/AUU, TTG/UUG (see Touriol et al. Biology of the Cell 95 (2003) 169- 15 178 and Matsuda and Mauro PLoS ONE, 20105:11; the contents of each of which are herein incorporated by reference in its entirety). As a non-limiting example, the translation of a polynucleotide begins on the alternative start codon ACG. As another non-limiting example, polynucleotide translation begins on the alternative start codon CTG or CUG. As yet another non-limiting example, 20 the translation of a polynucleotide begins on the alternative start codon GTG or GUG. Nucleotides flanking a codon that initiates translation such as, but not limited to, a start codon or an alternative start codon, are known to affect the translation efficiency, the length and/or the structure of the polynucleotide. (See, e.g., Matsuda and Mauro PLoS ONE, 20105:11; the contents of which are herein incorporated by reference in its 25 entirety). Masking any of the nucleotides flanking a codon that initiates translation can be used to alter the position of translation initiation, translation efficiency, length and/or structure of a polynucleotide. In some cases, a masking agent can be used near the start codon or alternative start codon in order to mask or hide the codon to reduce the probability of translation initiation at the 110 Attorney Docket No.: 45817-0177WO1 / MTX980.20 masked start codon or alternative start codon. Non-limiting examples of masking agents include antisense locked nucleic acids (LNA) polynucleotides and exon-junction complexes (EJCs) (See, e.g., Matsuda and Mauro describing masking agents LNA polynucleotides and EJCs (PLoS ONE, 20105:11); the contents of which are herein 5 incorporated by reference in its entirety). In another case, a masking agent can be used to mask a start codon of a polynucleotide in order to increase the likelihood that translation will initiate on an alternative start codon. In some cases, a masking agent can be used to mask a first start codon or alternative start codon in order to increase the chance that translation will initiate on a start codon or 10 alternative start codon downstream to the masked start codon or alternative start codon. In some instances, a start codon or alternative start codon can be located within a perfect complement for a miRNA binding site. The perfect complement of a miRNA binding site can help control the translation, length and/or structure of the polynucleotide similar to a masking agent. As a non-limiting example, the start codon or alternative start 15 codon can be located in the middle of a perfect complement for a miRNA binding site. The start codon or alternative start codon can be located after the first nucleotide, second nucleotide, third nucleotide, fourth nucleotide, fifth nucleotide, sixth nucleotide, seventh nucleotide, eighth nucleotide, ninth nucleotide, tenth nucleotide, eleventh nucleotide, twelfth nucleotide, thirteenth nucleotide, fourteenth nucleotide, fifteenth nucleotide, 20 sixteenth nucleotide, seventeenth nucleotide, eighteenth nucleotide, nineteenth nucleotide, twentieth nucleotide or twenty-first nucleotide. In another instance, the start codon of a polynucleotide can be removed from the polynucleotide sequence in order to have the translation of the polynucleotide begin on a codon that is not the start codon. Translation of the polynucleotide can begin on the 25 codon following the removed start codon or on a downstream start codon or an alternative start codon. In a non-limiting example, the start codon ATG or AUG is removed as the first 3 nucleotides of the polynucleotide sequence in order to have translation initiate on a downstream start codon or alternative start codon. The polynucleotide sequence where the start codon was removed can further comprise at least 111 Attorney Docket No.: 45817-0177WO1 / MTX980.20 one masking agent for the downstream start codon and/or alternative start codons in order to control or attempt to control the initiation of translation, the length of the polynucleotide and/or the structure of the polynucleotide. 5 Stop Codon Region The disclosure also includes a polynucleotide that comprises both a stop codon region and the polynucleotide described herein (e.g., a polynucleotide comprising a nucleotide sequence encoding a GPC3 binding CAR protein described herein). In some cases, the polynucleotides of the disclosure can include at least two stop codons before 10 the 3′ untranslated region (UTR). The stop codon can be selected from TGA, TAA and TAG in the case of DNA, or from UGA, UAA and UAG in the case of RNA. In some instances, the polynucleotides of the present disclosure include the stop codon TGA in the case or DNA, or the stop codon UGA in the case of RNA, and one additional stop codon. In a further instance, the addition stop codon can be TAA or UAA. In another 15 case, the polynucleotides of the present disclosure include three consecutive stop codons, four stop codons, or more. In some instances, the stop codon is provided as part of the 3’UTR. In some cases, the 3’UTR includes a stop cassette. 20 Combination of mRNA elements Any of the polynucleotides disclosed herein can comprise one, two, three, or all of the following elements: (a) a 5′-UTR, e.g., as described herein; (b) a coding region comprising a stop element (e.g., as described herein); (c) a 3′-UTR (e.g., as described herein) and; optionally (d) a 3′ stabilizing region, e.g., as described herein. Also disclosed 25 herein are LNP compositions comprising the same. In one instance, a polynucleotide of the disclosure comprises (a) a 5′ UTR described in Table 7, SEQ ID NO:7, or a variant or fragment thereof and (b) a coding region comprising a stop element provided herein. In one case, the polynucleotide further comprises a cap structure, e.g., as described herein, or a poly A tail, e.g., as described 112 Attorney Docket No.: 45817-0177WO1 / MTX980.20 herein. In one case, the polynucleotide further comprises a 3′ stabilizing region, e.g., as described herein. In another instance, a polynucleotide of the disclosure comprises (a) a 5′ UTR described in Table 7, SEQ ID NO:7, or a variant or fragment thereof and (c) a 3′ UTR 5 described in Table 8, any one of SEQ ID NOs: 10 to 12, or a variant or fragment thereof. In one case, the polynucleotide further comprises a cap structure, e.g., as described herein, or a poly A tail, e.g., as described herein. In another case, the polynucleotide further comprises a 3′ stabilizing region, e.g., as described herein. In another instance, a polynucleotide of the disclosure comprises (c) a 3′ UTR 10 described in Table 8, any one of SEQ ID NOs: 10 to 12, or a variant or fragment thereof and (b) a coding region comprising a stop element provided herein. In one case, the polynucleotide comprises a sequence provided in Table 9. In another case, the polynucleotide further comprises a cap structure, e.g., as described herein, or a poly A tail, e.g., as described herein. In another case, the polynucleotide further comprises a 3′ 15 stabilizing region, e.g., as described herein. In another instance, a polynucleotide of the disclosure comprises (a) a 5′ UTR described in Table 7, SEQ ID NO: 7, or a variant or fragment thereof; (b) a coding region comprising a stop element provided herein; and (c) a 3′ UTR described in Table 8, any one of SEQ ID NOs: 10 to 12, or a variant or fragment thereof. In one case, the 20 polynucleotide further comprises a cap structure, e.g., as described herein, or a poly A tail, e.g., as described herein. In another case, the polynucleotide further comprises a 3′ stabilizing region, e.g., as described herein. In another instance, a polynucleotide of the disclosure comprises (a) a 5′ UTR described in Table 7, SEQ ID NO: 7, or a variant or fragment thereof, (b) a coding region 25 comprising a stop element provided herein; and (c) a 3′ UTR comprising the sequence of SEQ ID NO:10. In one case, the polynucleotide further comprises a cap structure, e.g., as described herein, or a poly A tail, e.g., as described herein. In one instance, a polynucleotide of this disclosure comprises or consists of a sequence provided in any one of SEQ ID NOs.: 120-134. 113 Attorney Docket No.: 45817-0177WO1 / MTX980.20 Table 9: Exemplary 3′ UTR and stop element sequences SEQ ID Sequence NO information Sequence C C C C C C C C C C C C C C C 114 Attorney Docket No.: 45817-0177WO1 / MTX980.20 129 3′ UTR with C10 UAAAGCUCCAUAAAGUAGGAAACACUACAGCUGG stop (underlined) AGCCUCGGUGGCCUAGCUUCUUGCCCCUUGGGCC C A G C C A C C A C C G C U C C A C oynuceot e omprsng an m nco ng a n ng roten In certain instances, a polynucleotide of the present disclosure, for example a polynucleotide comprising an mRNA nucleotide sequence encoding a GPC3 Binding 5 CAR protein described herein, comprises from 5′ to 3′ end: (i) a 5′ cap such as any of the caps provided above; (ii) a 5′ UTR, such as any of the 5’UTR sequences provided above; 115 Attorney Docket No.: 45817-0177WO1 / MTX980.20 (iii) an ORF encoding a GPC3 Binding CAR protein described herein (e.g., SEQ ID NO:5 or 6), wherein the ORF has at least 90%, at least 95%, at least 97%, at least 98%, at least 99%, or 100% sequence identity to the sequence of SEQ ID NO:8 or 9; (iv) at least one stop codon (assuming it is not present at the 5’ end of the 5 3’UTR); (v) a 3′ UTR, such as any of the 3’UTR sequences provided above; and (vi) a poly A tail, such as any poly A sequence provided above. In some instances, the polynucleotide further comprises a miRNA binding site, e.g., one or more (e.g., 1, 2, 3) miRNA binding sites that bind to miRNA-142 or miR- 10 122. In some cases, the 5′ UTR comprises the miRNA binding site. In some cases, the 3′ UTR comprises the miRNA binding site. In some instances, the 3’UTR and/or the poly A tail include an IDR sequence. In some instances, a polynucleotide of the present disclosure comprises a nucleotide sequence encoding a polypeptide sequence at least 70%, at least 80%, at least 15 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96% , at least 97%, at least 98%, at least 99%, or 100% identical to the amino acid sequence of SEQ ID NO:5. In some instances, a polynucleotide of the present disclosure comprises a 20 nucleotide sequence encoding a polypeptide sequence at least 70%, at least 80%, at least 81%, at least 82%, at least 83%, at least 84%, at least 85%, at least 86%, at least 87%, at least 88%, at least 89%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96% , at least 97%, at least 98%, at least 99%, or 100% identical to the amino acid sequence of SEQ ID NO:6. 25 In some cases, a polynucleotide of the present disclosure, for example a polynucleotide comprising an mRNA nucleotide sequence encoding a polypeptide, comprises (1) a 5′ cap such as provided above, for example, comprising m⁷Gp-ppGm, (2) a 5′ UTR, (3) a nucleotide sequence ORF of at least 90% identity to the sequence of SEQ ID NO:8, (3) a stop codon (if not present at the 5’end of the 3’UTR), (4) a 3′UTR, and (5) 116 Attorney Docket No.: 45817-0177WO1 / MTX980.20 a poly A tail provided above, for example, a poly A tail of SEQ ID NO:117 or A100- UCUAG-A20-inverted deoxy-thymidine (SEQ ID NO:13). In some cases, a polynucleotide of the present disclosure, for example a polynucleotide comprising an mRNA nucleotide sequence encoding a polypeptide, 5 comprises (1) a 5′ cap such as provided above, for example, m⁷Gp-ppGm-A, (2) a 5′ UTR, (3) a nucleotide sequence ORF of at least 95% identity to the sequence of SEQ ID NO:8, (3) a stop codon (if not present at the 5’end of the 3’UTR), (4) a 3′UTR, and (5) a poly A tail provided above, for example, a poly A tail of SEQ ID NO:117 or A100- UCUAG-A20-inverted deoxy-thymidine (SEQ ID NO:13). 10 In some cases, a polynucleotide of the present disclosure, for example a polynucleotide comprising an mRNA nucleotide sequence encoding a polypeptide, comprises (1) a 5′ cap such as provided above, for example, m⁷Gp-ppGm-A, (2) a 5′ UTR, (3) a nucleotide sequence ORF of SEQ ID NO:8 or 9, (3) a stop codon (if not present at the 5’end of the 3’UTR), (4) a 3′UTR, and (5) a poly A tail provided above, for 15 example, a poly A tail of SEQ ID NO:117 or A100-UCUAG-A20-inverted deoxy- thymidine (SEQ ID NO:13). In certain instances, all uracils in the polynucleotide (e.g., mRNA) described herein are replaced by N1-methylpseudouracil. 20 Exemplary mRNA Encoding a GPC3 Binding CAR Provided in Table 10 below is the nucleic acid sequence information for a non- limiting example of a GPC3 binding CAR of this disclosure. In one instance, the 3’UTR comprises or consists of the nucleic acid sequence of SEQ ID NO:141. 25 Table 10 - Nucleic Acid Details of an Exemplary anti-GPC3 VHH CAR Description Sequence SEQ O Attorney Docket No.: 45817-0177WO1 / MTX980.20 ORF (without GAAGUCCAACUGGUUGAGAGCGGCGGCGGACUGGUUCAGCCCGGC 8 signal GGAAGCCUUCGUCUGAGCUGUGCCGCCAGCGGCUUCACCUUCAGC AGCUACGCCAUGAGCUGGGUGAGGCAGGCCCCUGGAAAGGAGCCC Attorney Docket No.: 45817-0177WO1 / MTX980.20 UCCUGCAXXXXXXXXXXXXXXXGUGGUCUUUGAAUAAAGUCUGA GUGGGCGGC (wherein X is A, C, U or G). Note that the total number of X’s i th b 9 th h 15 t Methods of Making Polynucleotides 5 The present disclosure also provides methods for making a polynucleotide of the disclosure (e.g., a polynucleotide comprising a nucleotide sequence encoding a GPC3 binding CAR protein described herein) or a complement thereof. In some aspects, a polynucleotide (e.g., a RNA, e.g., an mRNA) disclosed herein, and encoding a GPC3 binding CAR protein of the disclosure, can be constructed using in 10 vitro transcription (IVT). In other aspects, a polynucleotide (e.g., a RNA, e.g., an mRNA) disclosed herein, and encoding a GPC3 binding CAR protein of the disclosure, can be constructed by chemical synthesis using an oligonucleotide synthesizer. In other aspects, a polynucleotide (e.g., a RNA, e.g., an mRNA) disclosed herein, and encoding a GPC3 binding CAR protein of the disclosure is made by using a host cell. 15 In certain aspects, a polynucleotide (e.g., a RNA, e.g., an mRNA) disclosed herein, and encoding a GPC3 binding CAR protein of the disclosure is made by one or more combination of the IVT, chemical synthesis, host cell expression, or any other methods known in the art. Naturally occurring nucleosides, non-naturally occurring nucleosides, or 20 combinations thereof, can totally or partially naturally replace occurring nucleosides present in the candidate nucleotide sequence and can be incorporated into a sequence- optimized nucleotide sequence (e.g., a RNA, e.g., an mRNA) encoding a GPC3 binding CAR protein of the disclosure. The resultant polynucleotides, e.g., mRNAs, can then be examined for their ability to produce protein and/or produce a therapeutic outcome. 25 119 Attorney Docket No.: 45817-0177WO1 / MTX980.20 Pharmaceutical Compositions and Formulations The present disclosure provides pharmaceutical compositions and formulations that comprise any of the polynucleotides described above. In some cases, the composition or formulation further comprises a delivery agent. 5 In some instances, the composition or formulation can contain a polynucleotide comprising a sequence optimized nucleic acid sequence disclosed herein which encodes a GPC3 binding CAR protein described herein. In some cases, the composition or formulation can contain a polynucleotide (e.g., a RNA, e.g., an mRNA) comprising a polynucleotide (e.g., an ORF) having significant sequence identity to a sequence 10 optimized nucleic acid sequence disclosed herein which encodes a GPC3 binding CAR protein of the disclosure. In some cases, the polynucleotide further comprises a miRNA binding site, e.g., a miRNA binding site that binds miR-126, miR-142, miR-122, miR- 144, miR-146, miR-150, miR-155, miR-16, miR-21, miR-223, miR-24, miR-27, or miR- 26a. 15 Pharmaceutical compositions or formulation can optionally comprise one or more additional active substances, e.g., therapeutically and/or prophylactically active substances. Pharmaceutical compositions or formulation can be sterile and/or pyrogen- free. General considerations in the formulation and/or manufacture of pharmaceutical agents can be found, for example, in Remington: The Science and Practice of Pharmacy 20 21^st ed., Lippincott Williams & Wilkins, 2005 (incorporated herein by reference in its entirety). In some cases, compositions are administered to humans, human patients or subjects. For the purposes of the present disclosure, the phrase "active ingredient" generally refers to polynucleotides to be delivered as described herein. Formulations and pharmaceutical compositions described herein can be prepared 25 by any method known or hereafter developed in the art of pharmacology. In general, such preparatory methods include the step of associating the active ingredient with an excipient and/or one or more other accessory ingredients, and then, if necessary and/or desirable, dividing, shaping and/or packaging the product into a desired single- or multi- dose unit. 120 Attorney Docket No.: 45817-0177WO1 / MTX980.20 A pharmaceutical composition or formulation in accordance with the present disclosure can be prepared, packaged, and/or sold in bulk, as a single unit dose, and/or as a plurality of single unit doses. As used herein, a "unit dose" refers to a discrete amount of the pharmaceutical composition comprising a predetermined amount of the active 5 ingredient. The amount of the active ingredient is generally equal to the dosage of the active ingredient that would be administered to a subject and/or a convenient fraction of such a dosage such as, for example, one-half or one-third of such a dosage. Relative amounts of the active ingredient, the pharmaceutically acceptable excipient, and/or any additional ingredients in a pharmaceutical composition in 10 accordance with the present disclosure can vary, depending upon the identity, size, and/or condition of the subject being treated and further depending upon the route by which the composition is to be administered. In some cases, the compositions and formulations described herein can contain at least one polynucleotide of the disclosure. As a non-limiting example, the composition or 15 formulation can contain 1, 2, 3, 4 or 5 polynucleotides of the disclosure. In some cases, the compositions or formulations described herein can comprise more than one type of polynucleotide. In some cases, the composition or formulation can comprise a polynucleotide in linear and circular form. In another case, the composition or formulation can comprise a circular polynucleotide and an in vitro transcribed (IVT) 20 polynucleotide. In yet another case, the composition or formulation can comprise an IVT polynucleotide, a chimeric polynucleotide and a circular polynucleotide. Although the descriptions of pharmaceutical compositions and formulations provided herein are principally directed to pharmaceutical compositions and formulations that are suitable for administration to humans, it will be understood by the skilled artisan that 25 such compositions are generally suitable for administration to any other animal, e.g., to non-human animals, e.g. non-human mammals. Also provided are pharmaceutical formulations that comprise a polynucleotide described herein (e.g., a polynucleotide comprising a nucleotide sequence encoding a GPC3 binding CAR protein of the disclosure). The polynucleotides described herein can 121 Attorney Docket No.: 45817-0177WO1 / MTX980.20 be formulated using one or more excipients to: (1) increase stability; (2) increase cell transfection; (3) permit the sustained or delayed release (e.g., from a depot formulation of the polynucleotide); (4) alter the biodistribution (e.g., target the polynucleotide to specific tissues or cell types); (5) increase the translation of encoded protein in vivo; and/or (6) 5 alter the release profile of encoded protein in vivo. In some cases, the pharmaceutical formulation further comprises a delivery agent. In some cases, the delivery agent comprises an ionizable amino lipid, a helper lipid, a sterol (e.g., Cholesterol), and a PEG lipid (e.g., PEG-DMG), e.g., with a mole ratio in the range of about (i) 40-50 mol% ionizable amino lipid, optionally 45-50 mol% ionizable amino lipid, for example, 45-46 10 mol%, 46-47 mol%, 47-48 mol%, 48-49 mol%, or 49-50 mol% for example about 45 mol%, 45.5 mol%, 46 mol%, 46.5 mol%, 47 mol%, 47.5 mol%, 48 mol%, 48.5 mol%, 49 mol%, or 49.5 mol%; (ii) 30-45 mol% sterol (e.g., cholesterol), optionally 35-42 mol% sterol, for example, 30-31 mol%, 31-32 mol%, 32-33 mol%, 33-34 mol%, 35-35 mol%, 35-36 mol%, 36-37 mol%, 37-38 mol%, 38-39 mol%, or 39-40 mol%, or 40-42 mol% 15 sterol; (iii) 5-15 mol% helper lipid (e.g., DSPC), optionally 10-15 mol% helper lipid, for example, 5-6 mol%, 6-7 mol%, 7-8 mol%, 8-9 mol%, 9-10 mol%, 10-11 mol%, 11-12 mol%, 12-13 mol%, 13-14 mol%, or 14-15 mol% helper lipid; and (iv) 1-5% PEG lipid (e.g., PEG-DMG), optionally 1-5 mol% PEG lipid, for example 1.5 to 2.5 mol%, 1-2 mol%, 2-3 mol%, 3-4 mol%, or 4-5 mol% PEG lipid. In some cases, the delivery agent 20 comprises Cholesterol, and DSPC. In certain cases, the delivery agent comprises Compound II, Compound IV, Compound I, and Cholesterol (e.g., 48 mol% Compound II, 11 mol% Compound IV, 39 mol% cholesterol, and 2 mol% Compound I). In other cases, the delivery agent comprises Compound II, Compound IV, PEG-DMG, and Cholesterol (e.g., 48 mol% Compound II,11 mol% Compound IV, 39.5 mol% cholesterol, and 1.5 25 mol% PEG-DMG). In some cases, the delivery agent comprises Compound III, Compound IV, Cholesterol, Compound I, and Compound V (e.g., 39.70 mol% Compound III, 18.70 mol % Compound IV, 34.50 mol % Cholesterol, 3.00 mol % Compound I, and 4.10 mol % Compound V). 122 Attorney Docket No.: 45817-0177WO1 / MTX980.20 A pharmaceutically acceptable excipient, as used herein, includes, but are not limited to, any and all solvents, dispersion media, or other liquid vehicles, dispersion or suspension aids, diluents, granulating and/or dispersing agents, surface active agents, isotonic agents, thickening or emulsifying agents, preservatives, binders, lubricants or oil, 5 coloring, sweetening or flavoring agents, stabilizers, antioxidants, antimicrobial or antifungal agents, osmolality adjusting agents, pH adjusting agents, buffers, chelants, cryoprotectants, and/or bulking agents, as suited to the particular dosage form desired. Various excipients for Formulating pharmaceutical compositions and techniques for preparing the composition are known in the art (see Remington: The Science and Practice 10 of Pharmacy, 21st Edition, A. R. Gennaro (Lippincott, Williams & Wilkins, Baltimore, MD, 2006; incorporated herein by reference in its entirety). Exemplary diluents include, but are not limited to, calcium or sodium carbonate, calcium phosphate, calcium hydrogen phosphate, sodium phosphate, lactose, sucrose, cellulose, microcrystalline cellulose, kaolin, mannitol, sorbitol, etc., and/or combinations 15 thereof. Exemplary surface active agents and/or emulsifiers include, but are not limited to, natural emulsifiers (e.g., acacia, agar, alginic acid, sodium alginate, tragacanth, chondrux, cholesterol, xanthan, pectin, gelatin, egg yolk, casein, wool fat, cholesterol, wax, and lecithin), sorbitan fatty acid esters (e.g., polyoxyethylene sorbitan monooleate 20 [TWEEN®80], sorbitan monopalmitate [SPAN®40], glyceryl monooleate, polyoxyethylene esters, polyethylene glycol fatty acid esters (e.g., CREMOPHOR®), polyoxyethylene ethers (e.g., polyoxyethylene lauryl ether [BRIJ®30]), PLUORINC®F 68, POLOXAMER®188, etc. and/or combinations thereof. Exemplary binding agents include, but are not limited to, starch, gelatin, sugars (e.g., 25 sucrose, glucose, dextrose, dextrin, molasses, lactose, lactitol, mannitol), amino acids (e.g., glycine), natural and synthetic gums (e.g., acacia, sodium alginate), ethylcellulose, hydroxyethylcellulose, hydroxypropyl methylcellulose, etc., and combinations thereof. Oxidation is a potential degradation pathway for mRNA, especially for liquid mRNA formulations. In order to prevent oxidation, antioxidants can be added to the 123 Attorney Docket No.: 45817-0177WO1 / MTX980.20 formulations. Exemplary antioxidants include, but are not limited to, alpha tocopherol, ascorbic acid, ascorbyl palmitate, benzyl alcohol, butylated hydroxyanisole, m-cresol, methionine, butylated hydroxytoluene, monothioglycerol, sodium or potassium metabisulfite, propionic acid, propyl gallate, sodium ascorbate, etc., and combinations 5 thereof. Exemplary chelating agents include, but are not limited to, ethylenediaminetetraacetic acid (EDTA), citric acid monohydrate, disodium edetate, fumaric acid, malic acid, phosphoric acid, sodium edetate, tartaric acid, trisodium edetate, etc., and combinations thereof. 10 Exemplary antimicrobial or antifungal agents include, but are not limited to, benzalkonium chloride, benzethonium chloride, methyl paraben, ethyl paraben, propyl paraben, butyl paraben, benzoic acid, hydroxybenzoic acid, potassium or sodium benzoate, potassium or sodium sorbate, sodium propionate, sorbic acid, etc., and combinations thereof. 15 Exemplary preservatives include, but are not limited to, vitamin A, vitamin C, vitamin E, beta-carotene, citric acid, ascorbic acid, butylated hydroxyanisol, ethylenediamine, sodium lauryl sulfate (SLS), sodium lauryl ether sulfate (SLES), etc., and combinations thereof. In some cases, the pH of polynucleotide solutions is maintained between pH 5 and pH 8 20 to improve stability. Exemplary buffers to control pH can include, but are not limited to sodium phosphate, sodium citrate, sodium succinate, histidine (or histidine-HCl), sodium malate, sodium carbonate, etc., and/or combinations thereof. Exemplary lubricating agents include, but are not limited to, magnesium stearate, calcium stearate, stearic acid, silica, talc, malt, hydrogenated vegetable oils, polyethylene 25 glycol, sodium benzoate, sodium or magnesium lauryl sulfate, etc., and combinations thereof. The pharmaceutical composition or formulation described here can contain a cryoprotectant to stabilize a polynucleotide described herein during freezing. Exemplary 124 Attorney Docket No.: 45817-0177WO1 / MTX980.20 cryoprotectants include, but are not limited to mannitol, sucrose, trehalose, lactose, glycerol, dextrose, etc., and combinations thereof. The pharmaceutical composition or formulation described here can contain a bulking agent in lyophilized polynucleotide formulations to yield a "pharmaceutically 5 elegant" cake, stabilize the lyophilized polynucleotides during long term (e.g., 36 month) storage. Exemplary bulking agents of the present disclosure can include, but are not limited to sucrose, trehalose, mannitol, glycine, lactose, raffinose, and combinations thereof. In some cases, the pharmaceutical composition or formulation further comprises a 10 delivery agent. The delivery agent of the present disclosure can include, without limitation, liposomes, lipid nanoparticles, lipidoids, polymers, lipoplexes, microvesicles, exosomes, peptides, proteins, cells transfected with polynucleotides, hyaluronidase, nanoparticle mimics, nanotubes, conjugates, and combinations thereof. 15 Delivery Agents Lipid Compound The present disclosure provides pharmaceutical compositions with advantageous properties. The lipid compositions described herein may be advantageously used in lipid nanoparticle compositions for the delivery of therapeutic and/or prophylactic agents, e.g., 20 mRNAs, to mammalian cells or organs. For example, the lipids described herein have little or no immunogenicity. For example, the lipid compounds disclosed herein have a lower immunogenicity as compared to a reference lipid (e.g., MC3, KC2, or DLinDMA). For example, a formulation comprising a lipid disclosed herein and a therapeutic or prophylactic agent, e.g., mRNA, has an increased therapeutic index as compared to a 25 corresponding formulation which comprises a reference lipid (e.g., MC3, KC2, or DLinDMA) and the same therapeutic or prophylactic agent. In certain embodiments, the present application provides pharmaceutical compositions comprising: 125 Attorney Docket No.: 45817-0177WO1 / MTX980.20 (a) a polynucleotide comprising a nucleotide sequence encoding a GPC3 binding CAR protein described herein; and (b) a delivery agent. In certain cases, the delivery agent comprises Compound II, Compound IV, 5 Compound I, and Cholesterol (e.g., 48 mol% Compound II, 11 mol% Compound IV, 39 mol% cholesterol, and 2 mol% Compound I). In other cases, the delivery agent comprises Compound II, Compound IV, PEG-DMG, and Cholesterol (e.g., 48 mol% Compound II,11 mol% Compound IV, 39.5 mol% cholesterol, and 1.5 mol% PEG-DMG). In some cases, the delivery agent comprises Compound III, Compound IV, Cholesterol, 10 Compound I, and Compound V (e.g., 39.70 mol% Compound III, 18.70 mol % Compound IV, 34.50 mol % Cholesterol, 3.00 mol % Compound I, and 4.10 mol % Compound V). Lipid Nanoparticle Formulations 15 In some embodiments, nucleic acids of the invention (e.g., mRNA encoding GPC3 binding CAR) are formulated in a lipid nanoparticle (LNP). Lipid nanoparticles typically comprise ionizable cationic lipid, non-cationic lipid, sterol and PEG lipid components along with the nucleic acid cargo of interest. The lipid nanoparticles of the invention can be generated using components, compositions, and methods as are 20 generally known in the art, see for example PCT/US2016/052352; PCT/US2016/068300; PCT/US2017/037551; PCT/US2015/027400; PCT/US2016/047406; PCT/US2016000129; PCT/US2016/014280; PCT/US2016/014280; PCT/US2017/038426; PCT/US2014/027077; PCT/US2014/055394; PCT/US2016/52117; PCT/US2012/069610; PCT/US2017/027492; PCT/US2016/059575 25 and PCT/US2016/069491 all of which are incorporated by reference herein in their entirety. Nucleic acids of the present disclosure (e.g., mRNA encoding GPC3 binding CAR) are typically formulated in lipid nanoparticle. In some embodiments, the lipid 126 Attorney Docket No.: 45817-0177WO1 / MTX980.20 nanoparticle comprises at least one ionizable cationic lipid, at least one non-cationic lipid, at least one sterol, and/or at least one polyethylene glycol (PEG)-modified lipid. In some embodiments, the lipid nanoparticle comprises a molar ratio of 20-60% ionizable cationic lipid. For example, the lipid nanoparticle may comprise a molar ratio 5 of 40-50 mol%, optionally 45-50 mol%, for example, 45-46 mol%, 46-47 mol%, 47-48 mol%, 48-49 mol%, or 49-50 mol%, for example about 45 mol%, 45.5 mol%, 46 mol%, 46.5 mol%, 47 mol%, 47.5 mol%, 48 mol%, 48.5 mol%, 49 mol%, or 49.5 mol% ionizable cationic lipid. In some embodiments, the lipid nanoparticle comprises a molar ratio of 5-25% non- 10 cationic lipid. For example, the lipid nanoparticle may comprise a molar ratio of 5-15 mol%, optionally 10-12 mol%, for example, 5-6 mol%, 6-7 mol%, 7-8 mol%, 8-9 mol%, 9-10 mol%, 10-11 mol%, 11-12 mol%, 12-13 mol%, 13-14 mol%, or 14-15 mol% non- cationic lipid. In some embodiments, the lipid nanoparticle comprises a molar ratio of 25-55% 15 sterol. For example, the lipid nanoparticle may comprise a molar ratio of 30-45 mol%, optionally 35-40 mol%, for example, 30-31 mol%, 31-32 mol%, 32-33 mol%, 33-34 mol%, 35-35 mol%, 35-36 mol%, 36-37 mol%, 38-38 mol%, 38-39 mol%, or 39-40 mol% sterol. In some embodiments, the lipid nanoparticle comprises a molar ratio of 0.5-15% 20 PEG-modified lipid. For example, the lipid nanoparticle may comprise a molar ratio of 1-5%, optionally 1-3 mol%, for example 1.5 to 2.5 mol%, 1-2 mol%, 2-3 mol%, 3-4 mol%, or 4-5 mol% PEG-modified lipid. In some embodiments, the lipid nanoparticle comprises a molar ratio of 20-60% ionizable cationic lipid, 5-25% non-cationic lipid, 25-55% sterol, and 0.5-15% PEG- 25 modified lipid. In some embodiments, the lipid nanoparticle comprises a molar ratio of 40-50% ionizable cationic lipid, 5-15% non-cationic lipid, 30-45% sterol, and 1-5% PEG-modified lipid. In some embodiments, the lipid nanoparticle comprises a molar ratio of 45-50% ionizable cationic lipid, 10-12% non-cationic lipid, 35-40% sterol, and 1-3% PEG-modified lipid. 127 Attorney Docket No.: 45817-0177WO1 / MTX980.20 In some embodiments, the lipid nanoparticle comprises a molar ratio of 45-50% ionizable cationic lipid, 10-12% non-cationic lipid, 35-40% sterol, and 1.5-2.5% PEG-modified lipid. 5 Ionizable amino lipids In some aspects, the disclosure relates to a compound of Formula (I): or its N-oxide, or a salt or isomer thereof, wherein R’branched is ; wherein denotes a point of attachment; 10 wherein Raα, Raβ, Ra ach indepe tly selected from the group consisting of H, C2-12 alkyl, and C2-12 alkenyl; R2 and R3 are each independently selected from the group consisting of C1-14 alkyl and C2-14 alkenyl; 15 R4 is selected from the group consisting of -(CH2)nOH, wherein n is selected from the group consistin , wherein denotes a point of attachment; wherein R s N(R)2; each R is independently selected from the group consisting of C1-6 alkyl, C2-3 alkenyl, and H; and n2 is selected from the group consisting of 1, 2, 3, 4, 5, 6, 20 7, 8, 9, and 10; each R5 is independently selected from the group consisting of C1-3 alkyl, C2-3 alkenyl, and H; 128 Attorney Docket No.: 45817-0177WO1 / MTX980.20 each R6 is independently selected from the group consisting of C1-3 alkyl, C2-3 alkenyl, and H; M and M’ are each independently selected from the group consisting of -C(O)O- and 5 -OC(O)-; R’ is a C1-12 alkyl or C2-12 alkenyl; l is selected from the group consisting of 1, 2, 3, 4, and 5; and m is selected from the group consisting of 5, 6, 7, 8, 9, 10, 11, 12, and 13. In some embodiments of the compounds of Formula (I), R’a is R’branched; 10 denotes a point of attachment; Raα, Raβ, Raγ, a h C1-14 alkyl; R4 is -(CH2)nOH; n is 2; each R5 is H; each R6 is H; M and M’ are each -C(O)O-; R’ is a C1-12 alkyl; l is 5; and m is 7. In some embodiments of the compounds of Formula (I), R’a is R’branched; 15 denotes a point of attachment; Raα, Raβ, Raγ, a h C1-14 alkyl; R4 is -(CH2)nOH; n is 2; each R5 is H; each R6 is H; M and M’ are each -C(O)O-; R’ is a C1-12 alkyl; l is 3; and m is 7. In some embodiments of the compounds of Formula (I), R’a is R’branched; 20 denotes a point of attachment; Raα is C2- 12 alky , , and R3 are each C1-14 alkyl; R4 is 129 Attorney Docket No.: 45817-0177WO1 / MTX980.20 ; R10 NH(C1-6 alkyl); n2 is 2; R5 is H; each R6 is H; M and M’ are a C1-12 alkyl; l is 5; and m is 7. In some embodiments of the compounds of Formula (I), R’a is R’branched; denotes a point of attachment; Raα, Raβ, 5 and Ra and R3 are each C1-14 alkyl; R4 is - (CH2)nOH; n is 2; each R5 is H; each R6 is H; M and M’ are each -C(O)O-; R’ is a C1- 12 alkyl; l is 5; and m is 7. In some embodiments, the compound of Formula (I) is selected from: nd n some em o ments, t e compoun o Formula (I) is: 130 Attorney Docket No.: 45817-0177WO1 / MTX980.20 (Compound II). d of Formula (I) is: . of Formula (I) is: 5 . of Formula (I) is: (Compound B). In some aspects, the disclosure relates to a compound of Formula (Ia): 10 or its N-oxide, or a salt or isomer thereof, herein R’branched is ; wherein denotes a point of attachment; wherein Raβ, Raγ, and a are eac ndependently se ected from the group consisting of H, C2-12 alkyl, and C2-12 alkenyl; 131 Attorney Docket No.: 45817-0177WO1 / MTX980.20 R2 and R3 are each independently selected from the group consisting of C1-14 alkyl and C2-14 alkenyl; R4 is selected from the group consisting of -(CH2)nOH wherein n is selected 5 from the group consistin , wherein denotes a R s N(R)2; each R is independently selected from the group consisting of C1-6 alkyl, C2-3 alkenyl, and H; and n2 is selected from the group consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10; 10 each R5 is independently selected from the group consisting of C1-3 alkyl, C2-3 alkenyl, and H; each R6 is independently selected from the group consisting of C1-3 alkyl, C2-3 alkenyl, and H; M and M’ are each independently selected from the group consisting of -C(O)O- 15 and -OC(O)-; R’ is a C1-12 alkyl or C2-12 alkenyl; l is selected from the group consisting of 1, 2, 3, 4, and 5; and m is selected from the group consisting of 5, 6, 7, 8, 9, 10, 11, 12, and 13. 20 In some aspects, the disclosure relates to a compound of Formula (Ib): or its N-oxide, or a salt or isomer thereof, herein 132 Attorney Docket No.: 45817-0177WO1 / MTX980.20 R’branched is ; wherein denotes a point of attachment; wherein Raα, Raβ, Ra ach indepe tly selected from the group consisting of H, C2-12 alkyl, and C2-12 alkenyl; R2 and R3 are each independently selected from the group consisting of C1-14 5 alkyl and C2-14 alkenyl; R4 is -(CH2)nOH, wherein n is selected from the group consisting of 1, 2, 3, 4, and 5; each R5 is independently selected from the group consisting of C1-3 alkyl, 10 C2-3 alkenyl, and H; each R6 is independently selected from the group consisting of C1-3 alkyl, C2-3 alkenyl, and H; M and M’ are each independently selected from the group consisting of -C(O)O- and 15 -OC(O)-; R’ is a C1-12 alkyl or C2-12 alkenyl; l is selected from the group consisting of 1, 2, 3, 4, and 5; and m is selected from the group consisting of 5, 6, 7, 8, 9, 10, 11, 12, and 13. In some embodiments of Formula (I) or (Ib), R’a is R’branched; R’branched is denotes a point of attachment; Raβ, Raγ, and Raδ are each H; R2 alkyl; R4 is -(CH2)nOH; n is 2; each R5 is H; each R6 is H; M and M’ are each -C(O)O-; R’ is a C1-12 alkyl; l is 5; and m is 7. In some embodiments of Formula (I) or (Ib), R’a is R’branched; R’branched is denotes a point of attachment; Raβ, Raγ, and Raδ are each H; 133 Attorney Docket No.: 45817-0177WO1 / MTX980.20 R2 and R3 are each C1-14 alkyl; R4 is -(CH2)nOH; n is 2; each R5 is H; each R6 is H; M and M’ are each -C(O)O-; R’ is a C1-12 alkyl; l is 3; and m is 7. In some embodiments of Formula (I) or (Ib), R’a is R’branched; R’branched is γ is H; In some aspects, the disclosure relates to a compound of Formula (Ic): or its N-oxide, or a salt or isomer thereof, herein denotes a point of attachment; tly selected from the group consisting of H, C2-12 alkyl, and C2-12 alkenyl; R2 and R3 are each independently selected from the group consisting of C1-14 alkyl and 15 C2-14 alkenyl; , wherein denotes a point of attachment; wherein R10 is N(R)2; each R is independently selected from the group consisting of C1-6 alkyl, C2-3 alkenyl, and H; n2 is selected from the group consisting of 1, 2, 3, 4, 5, 6, 7, 20 8, 9, and 10; 34 Attorney Docket No.: 45817-0177WO1 / MTX980.20 each R5 is independently selected from the group consisting of C1-3 alkyl, C2-3 alkenyl, and H; each R6 is independently selected from the group consisting of C1-3 alkyl, C2-3 alkenyl, and H; 5 M and M’ are each independently selected from the group consisting of -C(O)O- and -OC(O)-; R’ is a C1-12 alkyl or C2-12 alkenyl; l is selected from the group consisting of 1, 2, 3, 4, and 5; and 10 m is selected from the group consisting of 5, 6, 7, 8, 9, 10, 11, 12, and 13. In some embodiments ; denotes a point of attac , , 12 alkyl; R2 and R3 are each C1-14 alkyl denotes a point of attachment; R10 is NH(C1-6 al 6 is H; M and M’ are 15 each -C(O)O-; R’ is a C1-12 alkyl; l is 5; and m is 7. In some embodiments, the compound of Formula (Ic) is: (Compound A). p , o a compound of Formula (II): 135 Attorney Docket No.: 45817-0177WO1 / MTX980.20 of, nd 5 Raγ and Raδ are each independently selected from the group consisting of H, C1-12 alkyl, and C2-12 alkenyl, wherein at least one of Raγ and Raδ is selected from the group consisting of C1-12 alkyl and C2-12 alkenyl; Rbγ and Rbδ are each independently selected from the group consisting of H, C1-12 10 alkyl, and C2-12 alkenyl, wherein at least one of Rbγ and Rbδ is selected from the group consisting of C1-12 alkyl and C2-12 alkenyl; R2 and R3 are each independently selected from the group consisting of C1-14 alkyl and C2-14 alkenyl; R4 is selected from the group consisting of -(CH2)nOH wherein n is selected from the 15 group consisting , wherein denotes a point of attachment; wherein 136 Attorney Docket No.: 45817-0177WO1 / MTX980.20 R10 is N(R)2; each R is independently selected from the group consisting of C1-6 alkyl, C2-3 alkenyl, and H; and n2 is selected from the group consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10; each R’ independently is a C1-12 alkyl or C2-12 alkenyl; 5 Ya is a C3-6 carbocycle; R*”a is selected from the group consisting of C1-15 alkyl and C2-15 alkenyl; and s is 2 or 3; m is selected from 1, 2, 3, 4, 5, 6, 7, 8, and 9; l is selected from 1, 2, 3, 4, 5, 6, 7, 8, and 9. 10 In some aspects, the disclosure relates to a compound of Formula (II-a): of, ; 15 Raγ and Raδ are each independently selected from the group consisting of H, C1-12 alkyl, and C2-12 alkenyl, wherein at least one of Raγ and Raδ is selected from the group consisting of C1-12 alkyl and C2-12 alkenyl; Rbγ and Rbδ are each independently selected from the group consisting of H, C1-12 alkyl, and C2-12 alkenyl, wherein at least one of Rbγ and Rbδ is selected from the group 20 consisting of C1-12 alkyl and C2-12 alkenyl; R2 and R3 are each independently selected from the group consisting of C1-14 alkyl and C2-14 alkenyl; 137 Attorney Docket No.: 45817-0177WO1 / MTX980.20 R4 is selected from the group consisting of -(CH2)nOH wherein n is selected from the group consisting , wherein d R10 is N 2; each R is independently selected from the group consisting of C1-6 alkyl, 5 C2-3 alkenyl, and H; and n2 is selected from the group consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10; each R’ independently is a C1-12 alkyl or C2-12 alkenyl; m is selected from 1, 2, 3, 4, 5, 6, 7, 8, and 9; l is selected from 1, 2, 3, 4, 5, 6, 7, 8, and 9. 10 In some aspects, the disclosure relates to a compound of Formula (II-b): or its N-oxide, or a salt or isomer thereof, clic; wherein R’branched is: ’b is ; wherein denotes a point of attachment ; 15 Raγ and are each independently selected from the group consisting of C1-12 alkyl and C2-12 alkenyl; R2 and R3 are each independently selected from the group consisting of C1-14 alkyl and C2-14 alkenyl; R4 is selected from the group consisting of -(CH2)nOH wherein n is selected from the 20 , Attorney Docket No.: 45817-0177WO1 / MTX980.20 wherein denotes a point of attachment; wherein R10 is N(R)2; each R is independently selected from the group consisting of C1-6 alkyl, C2-3 alkenyl, and H; and n2 is selected from the group consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10; 5 each R’ independently is a C1-12 alkyl or C2-12 alkenyl; m is selected from 1, 2, 3, 4, 5, 6, 7, 8, and 9; l is selected from 1, 2, 3, 4, 5, 6, 7, 8, and 9. In some aspects, the disclosure relates to a compound of Formula (II-c): or its N-oxide, or a salt or isomer thereof, 10 clic; wherein R’branched is: ’b is ; wherein denotes a point of attachment ; wherein is selected from the group consisting of C1-12 alkyl and C2-12 alkenyl; R2 and R3 are each independently selected from the group consisting of C1-14 alkyl and 15 C2-14 alkenyl; R4 is selected from the group consisting of -(CH2)nOH wherein n is selected from the group consisting , wherein d enotes a point of attachment; wherein R10 is N(R)2; each R is independently selected from the group consisting of C1-6 alkyl, 20 C2-3 alkenyl, and H; and n2 is selected from the group consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10; 139 Attorney Docket No.: 45817-0177WO1 / MTX980.20 R’ is a C1-12 alkyl or C2-12 alkenyl; m is selected from 1, 2, 3, 4, 5, 6, 7, 8, and 9; l is selected from 1, 2, 3, 4, 5, 6, 7, 8, and 9. In some aspects, the disclosure relates to a compound of Formula (II-d): 5 or its N-oxide, or a salt or isomer thereof, clic; wherein R’branched is: ’b is ; wherein e o es a po o a ac ment wherein and Rbγ are each independently selected from the group consisting of C1-12 10 alkyl and C2-12 alkenyl; R4 is selected from the group consisting of -(CH2)nOH wherein n is selected from the group consisting , wherein d enotes a po nt o attac ment; w ere n R10 is N ; each R is independently selected from the group consisting of C1-6 alkyl, 15 C2-3 alkenyl, and H; and n2 is selected from the group consisting of 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10; each R’ independently is a C1-12 alkyl or C2-12 alkenyl; m is selected from 1, 2, 3, 4, 5, 6, 7, 8, and 9; l is selected from 1, 2, 3, 4, 5, 6, 7, 8, and 9. 20 In some aspects, the disclosure relates to a compound of Formula (II-e): 140 Attorney Docket No.: 45817-0177WO1 / MTX980.20 or its N-oxide, or a salt or isomer thereof, clic; wherein R’branched is: ’b is: ; wherein ment 5 wherein Raγ is selected from the group consisting of C1-12 alkyl and C2-12 alkenyl; R2 and R3 are each independently selected from the group consisting of C1-14 alkyl and C2-14 alkenyl; R4 is -(CH2)nOH wherein n is selected from the group consisting of 1, 2, 3, 4, and 5; R’ is a C1-12 alkyl or C2-12 alkenyl; 10 m is selected from 1, 2, 3, 4, 5, 6, 7, 8, and 9; l is selected from 1, 2, 3, 4, 5, 6, 7, 8, and 9. In some embodiments of the compound of Formula (II), (II-a), (II-b), (II-c), (II-d), or (II-e), m and l are each independently selected from 4, 5, and 6. In some embodiments of the compound of Formula (II), (II-a), (II-b), (II-c), (II-d), or (II-e), m and l are each 5. 15 In some embodiments of the compound of Formula (II), (II-a), (II-b), (II-c), (II-d), or (II- e), each R’ independently is a C1-12 alkyl. In some embodiments of the compound of Formula (II), (II-a), (II-b), (II-c), (II-d), or (II-e), each R’ independently is a C2-5 alkyl. In some embodiments of the compound of Formula (II), (II-a), (II-b), (II-c), (II-d), or (II-e), R’b is and R2 and R3 are each independently a C1-14 alkyl. In some 20 embodiments o pound of Formula (II), (II-a), (II-b), (II-c), (II-d), or (II-e), R’b is d R2 and R3 are each independently a C6-10 alkyl. In some embodiments 141 Attorney Docket No.: 45817-0177WO1 / MTX980.20 of the compound of Formula (II), (II-a), (II-b), (II-c), (II-d), or (II-e), R’b is: and R2 and R3 are each a C8 alkyl. In some embodiments of the compound of Formula (II), (II-a), (II-b), (II-c), (II-d), or (II-e), R’branched is R’b is: , Raγ is a C1-12 alkyl 5 and R2 and R3 are each kyl e embodiments of the compound of Formula (II), (II-a), (II-b), (II-c), (II-d), or (II-e), R’branched is: ’ , Raγ is a C2-6 alkyl and R2 and R3 are each e embodiments of the compound of Formula (II), (II-a), (II-b), (II-c), (II-d), or (II-e), R’branched i R’b is: 10 , Raγ is a C2-6 alkyl, and R2 and R3 are each a C8 alkyl. n some embodiments of the compound of Formula (II), (II-a), (II-b), (II-c), (II-d), or (II-e), R’branched is ’b i nd Raγ and Rbγ are each a C1-12 alkyl. s of ula (II), (II-a), (II-b), (II-c), (II-d), or (II-e), R’branched is ’b i 15 , and Raγ and Rbγ are each a C2-6 alkyl. In some embodiments of the compound of Formula (II), (II-a), (II-b), (II-c), (II-d), or (II-e), m and l are each independently selected from 4, 5, and 6 and each R’ independently is a C1-12 alkyl. In some embodiments of the compound of Formula (II), (II-a), (II-b), (II-c), (II-d), or (II-e), m and l are each 5 and each R’ independently is a C2- 20 5 alkyl. 142 Attorney Docket No.: 45817-0177WO1 / MTX980.20 In some embodiments of the compound of Formula (II), (II-a), (II-b), (II-c), (II-d), or (II-e), R’branched is: R’b is d l are each independently selected R’ i lkyl, and Raγ and Rbγ are each a C1-12 alkyl. In some embodiments of the compound of Formula (II), ’ R’b is: , m and l are each 5, each R’ independently is a C2-5 alkyl, and Raγ a C2-6 alkyl. In some embodiments of the compound of Formula (II), (II-a), (II-b), (II-c), (II-d), or (II-e), R’branched is ’b is nd l are each 10 independently selected 1-1 1-12 alkyl and R2 and R3 are each independently a C6-10 alkyl. In some embodiments of the compound of Formula (II), (II-a), (II-b), (II-c), (II-d), or (II-e), R’branched i nd ’ , m and l are each 5, R’ is a C2-5 alkyl, Raγ is a C2-6 alkyl, and R2 and 8 alkyl. embodiments of the compound of Formula (II), (II-a), (II-b), (II-c), (II-d), , wherein R10 is NH(C1-6 alkyl) and n2 is 2. In nd of Formula (II), (II-a), (II-b), (II-c), (II-d), or (II-e), 2. Attorney Docket No.: 45817-0177WO1 / MTX980.20 In some embodiments of the compound of Formula (II), (II-a), (II-b), (II-c), (II-d), or (II-e), R’branched is: R’b is d l are each independently selected R’ i lkyl, Raγ and Rbγ are each a C1-12 alkyl , wherein R10 is NH(C1-6 5 alkyl), and n2 is 2. In som d of Formula (II), (II-a), (II-b), (II-c), (II-d), or (II-e), R’branched is ’b i , m and l are each 5, each R’ independe γ an 6 alkyl, , wherein R10 is NH(CH3) and n2 is 2. compound of Formula (II), (II-a), (II-b), (II-c), (II-d), 10 or (II-e), R’branched is ’b is d l are each independently selected 1-1 3 are each independently a C6-10 alkyl, Raγ is a C1-12 alky , wherein R10 is NH(C1-6 alkyl) and n2 is 2. In s ound of Formula (II), (II-a), (II-b), (II-c), (II-d), or (II-e), R’branched i nd 15 R’b is , m and l are each 5, R’ is a C2-5 alkyl, Raγ is a C2-6 alkyl, R2 and R3 144 Attorney Docket No.: 45817-0177WO1 / MTX980.20 are each a C8 alkyl, and R4 i , wherein R10 is NH(CH3) and n2 is 2. In some embodiments of the compound of Formula (II), (II-a), (II-b), (II-c), (II-d), or (II-e), R4 is -(CH2)nOH and n is 2, 3, or 4. In some embodiments of the compound of 5 Formula (II), (II-a), (II-b), (II-c), (II-d), or (II-e), R4 is -(CH2)nOH and n is 2. In some embodiments of the compound of Formula (II), (II-a), (II-b), (II-c), (II-d), or (II- e), R’branched is: ’b is d l are each independently sel eac -12 alkyl, Raγ and Rbγ are each a C1-12 alkyl, R4 is -(CH2)nOH, and n is 2, 3, or 4. In some embodiments 10 of the compound of Formula (II), (II-a), (II-b), (II-c), (II-d), or (II-e), R’branched is: R’b is: , m and l are each 5, each R’ independently 6 alkyl, R4 is -(CH2)nOH, and n is 2. In some aspects, the disclosure relates to a compound of Formula (II-f): or its N-oxide, or a salt or isomer thereof, 15 clic; wherein R’branched is: ’b is ; wherein denotes a point of attachment; Raγ is a C -12 alkyl; R2 and R3 are each independently a C1-14 alkyl; 145 Attorney Docket No.: 45817-0177WO1 / MTX980.20 R4 is -(CH2)nOH wherein n is selected from the group consisting of 1, 2, 3, 4, and 5; R’ is a C1-12 alkyl; m is selected from 4, 5, and 6; and l is selected from 4, 5, and 6. 5 In some embodiments of the compound of Formula (II-f), m and l are each 5, and n is 2, 3, or 4. In some embodiments of the compound of Formula (II-f) R’ is a C2-5 alkyl, Raγ is a C2-6 alkyl, and R2 and R3 are each a C6-10 alkyl. In some embodiments of the compound of Formula (II-f), m and l are each 5, n is 10 2, 3, or 4, R’ is a C2-5 alkyl, Raγ is a C2-6 alkyl, and R2 and R3 are each a C6-10 alkyl. In some aspects, the disclosure relates to a compound of Formula (II-g): ), wherein R’ is a C2-5 alkyl; and 15 R4 is selected from the group consisting of -(CH2)nOH wherein n is selected from the group consisting , wherein d enotes a point of attachment, R10 is NH(C1-6 alkyl), and n2 is selected from the up consisting of 1, 2, and 3. In some aspects, the disclosure relates to a compound of Formula (II-h): 20 ), wherein alkyl; 146 Attorney Docket No.: 45817-0177WO1 / MTX980.20 each R’ independently is a C2-5 alkyl; and R4 is selected from the group consisting of -(CH2)nOH wherein n is selected from the group consisting , wherein d H(C1-6 alkyl), and n2 is selected 5 from the up consisting of 1, 2, and 3. In some embodiments of the compound of Formula (II-g) or (II-h), R4 is , wherein d n2 is 2. In some embodiments of the compound of Formula (II-g) or (II-h), R4 is - 10 (CH2)2OH. In some aspects, the disclosure relates to a compound having the Formula (III): I), R1, R2, R3, R4, and R5 are independently selected from the group consisting of C5-20 15 alkyl, C5-20 alkenyl, -R”MR’, -R*YR”, -YR”, and -R*OR”; each M is independently selected from the group consisting of -C(O)O-, -OC(O)-, -OC(O)O-, -C(O)N(R’)-, -N(R’)C(O)-, -C(O)-, -C(S)-, -C(S)S-, -S C(S)-, -CH(OH)-, -P(O)(OR’)O-, -S(O)2-, an aryl group, and a heteroaryl group; 20 X1, X2, and X3 are independently selected from the group consisting of a bond, -CH2-, -(CH2)2-, -CHR-, -CHY-, -C(O)-, -C(O)O-, -OC(O)-, -C(O)-CH2-, -CH2-C(O)-, 147 Attorney Docket No.: 45817-0177WO1 / MTX980.20 -C(O)O-CH2-, -OC(O)-CH2-, -CH2-C(O)O-, -CH2-OC(O)-, -CH(OH)-, -C(S)-, and -CH(SH)-; each Y is independently a C3-6 carbocycle; each R* is independently selected from the group consisting of C1-12 alkyl and C2-12 5 alkenyl; each R is independently selected from the group consisting of C1-3 alkyl and a C3-6 carbocycle; each R’ is independently selected from the group consisting of C1-12 alkyl, C2-12 alkenyl, and H; and 10 each R” is independently selected from the group consisting of C3-12 alkyl and C3-12 alkenyl, and wherein: i) at least one of X1, X2, and X3 is not -CH2-; and/or ii) at least one of R1, R2, R3, R4, and R5 is -R”MR’. In some embodiments, R1, R2, R3, R4, and R5 are each C5-20 alkyl; X1 15 is -CH2-; and X2 and X3 are each -C(O)-. In some embodiments, the compound of Formula (III) is: (Compound VI), or a salt In one instance, the ionizable amino lipid is heptadecan-9-yl 8-((2- 20 hydroxyethyl)(8-(nonyloxy)-8-oxooctyl)amino)octanoate and has the structure of Compound II. In another instance, the ionizable amino lipid is 3-butylheptyl 8-((8-(heptadecan- 9-yloxy)-8-oxooctyl)(2-hydroxyethyl)amino)octanoate (Compound III) and has the following structure: 148 Attorney Docket No.: 45817-0177WO1 / MTX980.20 . Phospholipids The lipid composition of the lipid nanoparticle composition disclosed herein can 5 comprise one or more phospholipids, for example, one or more saturated or (poly)unsaturated phospholipids or a combination thereof. In general, phospholipids comprise a phospholipid moiety and one or more fatty acid moieties. A phospholipid moiety can be selected, for example, from the non-limiting group consisting of phosphatidyl choline, phosphatidyl ethanolamine, phosphatidyl glycerol, 10 phosphatidyl serine, phosphatidic acid, 2-lysophosphatidyl choline, and a sphingomyelin. A fatty acid moiety can be selected, for example, from the non-limiting group consisting of lauric acid, myristic acid, myristoleic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, linoleic acid, alpha-linolenic acid, erucic acid, phytanoic acid, arachidic acid, arachidonic acid, eicosapentaenoic acid, behenic acid, docosapentaenoic 15 acid, and docosahexaenoic acid. Particular phospholipids can facilitate fusion to a membrane. For example, a cationic phospholipid can interact with one or more negatively charged phospholipids of a membrane (e.g., a cellular or intracellular membrane). Fusion of a phospholipid to a membrane can allow one or more elements (e.g., a therapeutic agent) of a lipid- 20 containing composition (e.g., LNPs) to pass through the membrane permitting, e.g., delivery of the one or more elements to a target tissue. Non-natural phospholipid species including natural species with modifications and substitutions including branching, oxidation, cyclization, and alkynes are also contemplated. For example, a phospholipid can be functionalized with or cross-linked to 25 one or more alkynes (e.g., an alkenyl group in which one or more double bonds is 149 Attorney Docket No.: 45817-0177WO1 / MTX980.20 replaced with a triple bond). Under appropriate reaction conditions, an alkyne group can undergo a copper-catalyzed cycloaddition upon exposure to an azide. Such reactions can be useful in functionalizing a lipid bilayer of a nanoparticle composition to facilitate membrane permeation or cellular recognition or in conjugating a nanoparticle 5 composition to a useful component such as a targeting or imaging moiety (e.g., a dye). Phospholipids include, but are not limited to, glycerophospholipids such as phosphatidylcholines, phosphatidylethanolamines, phosphatidylserines, phosphatidylinositols, phosphatidylglycerols, and phosphatidic acids. Phospholipids also include phosphosphingolipid, such as sphingomyelin. 10 In some embodiments, a phospholipid of the invention comprises 1,2-distearoyl- sn-glycero-3-phosphocholine (DSPC), 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine (DOPE), 1,2-dilinoleoyl-sn-glycero-3-phosphocholine (DLPC), 1,2-dimyristoyl-sn-gly cero-phosphocholine (DMPC), 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC), l,2- dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), 1,2-diundecanoyl-sn-glycero- 15 phosphocholine (DUPC), 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), 1,2-di-O-octadecenyl-sn-glycero-3-phosphocholine (18:0 Diether PC), 1-oleoyl-2 cholesterylhemisuccinoyl-sn-glycero-3-phosphocholine (OChemsPC), 1-hexadecyl-sn- glycero-3-phosphocholine (C16 Lyso PC), 1,2-dilinolenoyl-sn-glycero-3- phosphocholine,1,2-diarachidonoyl-sn-glycero-3-phosphocholine, 1,2-20 didocosahexaenoyl-sn-glycero-3-phosphocholine, 1,2-diphytanoyl-sn-glycero-3- phosphoethanolamine (ME 16.0 PE), 1,2-distearoyl-sn-glycero-3-phosphoethanolamine, 1,2-dilinoleoyl-sn-glycero-3-phosphoethanolamine, 1,2-dilinolenoyl-sn-glycero-3- phosphoethanolamine, 1,2-diarachidonoyl-sn-glycero-3-phosphoethanolamine, 1,2- didocosahexaenoyl-sn-glycero-3-phosphoethanolamine, 1,2-dioleoyl-sn-glycero-3- 25 phospho-rac-(1-glycerol) sodium salt (DOPG), sphingomyelin, and mixtures thereof. In certain embodiments, a phospholipid useful or potentially useful in the present invention is an analog or variant of DSPC. In certain embodiments, a phospholipid useful or potentially useful in the present invention is a compound of Formula (IV): 150 Attorney Docket No.: 45817-0177WO1 / MTX980.20 or a salt thereof, wherein: each R1 is independently optionally substituted alkyl; or optionally two R1 are joined 5 together with the intervening atoms to form optionally substituted monocyclic carbocyclyl or optionally substituted monocyclic heterocyclyl; or optionally three R1 are joined together with the intervening atoms to form optionally substituted bicyclic carbocyclyl or optionally substitute bicyclic heterocyclyl; n is 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; 10 m is 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; A is of the Formula: ; each instance of L2 ionally substituted C1-6 alkylene, wherein one methylene unit of the optionally substituted C1-6 alkylene is optionally replaced with O, N(RN), S, C(O), C(O)N(RN), NRNC(O), C(O)O, OC(O), OC(O)O, - 15 OC(O)N(RN), NRNC(O)O, or NRNC(O)N(RN); each instance of R2 is independently optionally substituted C1-30 alkyl, optionally substituted C1-30 alkenyl, or optionally substituted C1-30 alkynyl; optionally wherein one or more methylene units of R2 are independently replaced with optionally substituted carbocyclylene, optionally substituted heterocyclylene, optionally substituted arylene,20 optionally substituted heteroarylene, N(RN), O, S, C(O), C(O)N(RN), NRNC(O), - NRNC(O)N(RN), C(O)O, OC(O), OC(O)O, OC(O)N(RN), NRNC(O)O, C(O)S, SC(O), C(=NRN), C(=NRN)N(RN), NRNC(=NRN), NRNC(=NRN)N(RN), C(S), C(S)N(RN), NRNC(S), NRNC(S)N(RN), S(O), OS(O), S(O)O, OS(O)O, OS(O)2, S(O)2O, OS(O)2O, N(RN)S(O), S(O)N(RN), N(RN)S(O)N(RN), OS(O)N(RN), N(RN)S(O)O, S(O)2, - 25 N(RN)S(O)2, S(O)2N(RN), N(RN)S(O)2N(RN), OS(O)2N(RN), or N(RN)S(O)2O; 151 Attorney Docket No.: 45817-0177WO1 / MTX980.20 each instance of RN is independently hydrogen, optionally substituted alkyl, or a nitrogen protecting group; Ring B is optionally substituted carbocyclyl, optionally substituted heterocyclyl, optionally substituted aryl, or optionally substituted heteroaryl; and 5 p is 1 or 2; provided that the compound is not of the Formula: , is independently unsubstituted alkyl, unsubstituted alkenyl, or unsubstituted alkynyl. 10 In some embodiments, the phospholipids may be one or more of the phospholipids described in U.S. Application No.62/520,530. Phospholipid Head Modifications In certain embodiments, a phospholipid useful or potentially useful in the present 15 invention comprises a modified phospholipid head (e.g., a modified choline group). In certain embodiments, a phospholipid with a modified head is DSPC, or analog thereof, with a modified quaternary amine. For example, in embodiments of Formula (IV), at least one of R1 is not methyl. In certain embodiments, at least one of R1 is not hydrogen or methyl. In certain embodiments, the compound of Formula (IV) is of one of the following 20 Formulae: , Attorney Docket No.: 45817-0177WO1 / MTX980.20 or a salt thereof, wherein: each t is independently 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; each u is independently 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; and each v is independently 1, 2, or 3. 5 In certain embodiments, a compound of Formula (IV) is of Formula (IV-a): or a salt thereof. In certain embodiments, a phospholipid useful or potentially useful in the present 10 invention comprises a cyclic moiety in place of the glyceride moiety. In certain embodiments, a phospholipid useful in the present invention is DSPC, or analog thereof, with a cyclic moiety in place of the glyceride moiety. In certain embodiments, the compound of Formula (IV) is of Formula (IV-b): , 15 or a salt thereof. Phospholipid Tail Modifications In certain embodiments, a phospholipid useful or potentially useful in the present 20 invention comprises a modified tail. In certain embodiments, a phospholipid useful or potentially useful in the present invention is DSPC, or analog thereof, with a modified tail. As described herein, a “modified tail” may be a tail with shorter or longer aliphatic chains, aliphatic chains with branching introduced, aliphatic chains with substituents introduced, aliphatic chains wherein one or more methylenes are replaced by cyclic or 25 heteroatom groups, or any combination thereof. For example, in certain embodiments, the compound of (IV) is of Formula (IV-a), or a salt thereof, wherein at least one instance of 153 Attorney Docket No.: 45817-0177WO1 / MTX980.20 R2 is each instance of R2 is optionally substituted C1-30 alkyl, wherein one or more methylene units of R2 are independently replaced with optionally substituted carbocyclylene, optionally substituted heterocyclylene, optionally substituted arylene, optionally substituted heteroarylene, N(RN), O, S, C(O), C(O)N(RN), NRNC(O), - 5 NRNC(O)N(RN), C(O)O, OC(O), OC(O)O, OC(O)N(RN), NRNC(O)O, C(O)S, SC(O), C(=NRN), C(=NRN)N(RN), NRNC(=NRN), NRNC(=NRN)N(RN), C(S), C(S)N(RN), NRNC(S), NRNC(S)N(RN), S(O), OS(O), S(O)O, OS(O)O, OS(O)2, S(O)2O, OS(O)2O, N(RN)S(O), S(O)N(RN), N(RN)S(O)N(RN), OS(O)N(RN), N(RN)S(O)O, S(O)2, - N(RN)S(O)2, S(O)2N(RN), N(RN)S(O)2N(RN), OS(O)2N(RN), or N(RN)S(O)2O. 10 In certain embodiments, the compound of Formula (IV) is of Formula (IV-c): c), or a sa each x is independently an integer between 0-30, inclusive; and each instance is G is independently selected from the group consisting of optionally 15 substituted carbocyclylene, optionally substituted heterocyclylene, optionally substituted arylene, optionally substituted heteroarylene, N(RN), O, S, C(O), C(O)N(RN), - NRNC(O), NRNC(O)N(RN), C(O)O, OC(O), OC(O)O, OC(O)N(RN), NRNC(O)O, - C(O)S, SC(O), C(=NRN), C(=NRN)N(RN), NRNC(=NRN), NRNC(=NRN)N(RN), - C(S), C(S)N(RN), NRNC(S), NRNC(S)N(RN), S(O), OS(O), S(O)O, OS(O)O, OS(O)2,20 S(O)2O, OS(O)2O, N(RN)S(O), S(O)N(RN), N(RN)S(O)N(RN), OS(O)N(RN), - N(RN)S(O)O, S(O)2, N(RN)S(O)2, S(O)2N(RN), N(RN)S(O)2N(RN), OS(O)2N(RN), or N(RN)S(O)2O. Each possibility represents a separate embodiment of the present invention. In certain embodiments, a phospholipid useful or potentially useful in the present 25 invention comprises a modified phosphocholine moiety, wherein the alkyl chain linking the quaternary amine to the phosphoryl group is not ethylene (e.g., n is not 2). Therefore, in certain embodiments, a phospholipid useful or potentially useful in the present 154 Attorney Docket No.: 45817-0177WO1 / MTX980.20 invention is a compound of Formula (IV), wherein n is 1, 3, 4, 5, 6, 7, 8, 9, or 10. For example, in certain embodiments, a compound of Formula (IV) is of one of the following Formulae: , 5 Alternative Lipids In certain embodiments, a phospholipid useful or potentially useful in the present invention comprises a modified phosphocholine moiety, wherein the alkyl chain linking 10 the quaternary amine to the phosphoryl group is not ethylene (e.g., n is not 2). Therefore, in certain embodiments, a phospholipid useful. In certain embodiments, an alternative lipid is used in place of a phospholipid of the present disclosure. In certain embodiments, an alternative lipid of the invention is oleic acid. 15 In certain embodiments, the alternative lipid is one of the following: , , Attorney Docket No.: 45817-0177WO1 / MTX980.20 , nd 5 Structural Lipids The lipid composition of a pharmaceutical composition disclosed herein can comprise one or more structural lipids. As used herein, the term "structural lipid" refers to sterols and also to lipids containing sterol moieties. 10 Incorporation of structural lipids in the lipid nanoparticle may help mitigate aggregation of other lipids in the particle. Structural lipids can be selected from the group including but not limited to, cholesterol, fecosterol, sitosterol, ergosterol, campesterol, stigmasterol, brassicasterol, tomatidine, tomatine, ursolic acid, alpha-tocopherol, hopanoids, phytosterols, steroids, and mixtures thereof. In some embodiments, the 15 structural lipid is a sterol. As defined herein, "sterols" are a subgroup of steroids consisting of steroid alcohols. In certain embodiments, the structural lipid is a steroid. In 156 Attorney Docket No.: 45817-0177WO1 / MTX980.20 certain embodiments, the structural lipid is cholesterol. In certain embodiments, the structural lipid is an analog of cholesterol. In certain embodiments, the structural lipid is alpha-tocopherol. In some embodiments, the structural lipids may be one or more of the structural 5 lipids described in U.S. Application No.62/520,530. Polyethylene Glycol (PEG)-Lipids The lipid composition of a pharmaceutical composition disclosed herein can comprise one or more a polyethylene glycol (PEG) lipid. 10 As used herein, the term “PEG-lipid” refers to polyethylene glycol (PEG)- modified lipids. Non-limiting examples of PEG-lipids include PEG-modified phosphatidylethanolamine and phosphatidic acid, PEG-ceramide conjugates (e.g., PEG- CerC14 or PEG-CerC20), PEG-modified dialkylamines and PEG-modified 1,2- diacyloxypropan-3-amines. Such lipids are also referred to as PEGylated lipids. For 15 example, a PEG lipid can be PEG-c-DOMG, PEG-DMG, PEG-DLPE, PEG-DMPE, PEG-DPPC, or a PEG-DSPE lipid. In some embodiments, the PEG-lipid includes, but not limited to 1,2-dimyristoyl- sn-glycerol methoxypolyethylene glycol (PEG-DMG), 1,2-distearoyl-sn-glycero-3- phosphoethanolamine-N-[amino(polyethylene glycol)] (PEG-DSPE), PEG-disteryl20 glycerol (PEG-DSG), PEG-dipalmetoleyl, PEG-dioleyl, PEG-distearyl, PEG- diacylglycamide (PEG-DAG), PEG-dipalmitoyl phosphatidylethanolamine (PEG-DPPE), or PEG-l,2-dimyristyloxlpropyl-3-amine (PEG-c-DMA). In one embodiment, the PEG-lipid is selected from the group consisting of a PEG- modified phosphatidylethanolamine, a PEG-modified phosphatidic acid, a PEG-modified25 ceramide, a PEG-modified dialkylamine, a PEG-modified diacylglycerol, a PEG- modified dialkylglycerol, and mixtures thereof. In some embodiments, the lipid moiety of the PEG-lipids includes those having lengths of from about C14 to about C22, preferably from about C14 to about C16. In some embodiments, a PEG moiety, for example an mPEG-NH2, has a size of about 1000, 157 Attorney Docket No.: 45817-0177WO1 / MTX980.20 2000, 5000, 10,000, 15,000 or 20,000 daltons. In one embodiment, the PEG-lipid is PEG2k-DMG. In one embodiment, the lipid nanoparticles described herein can comprise a PEG lipid which is a non-diffusible PEG. Non-limiting examples of non-diffusible PEGs 5 include PEG-DSG and PEG-DSPE. PEG-lipids are known in the art, such as those described in U.S. Patent No. 8158601 and International Publ. No. WO 2015/130584 A2, which are incorporated herein by reference in their entirety. In general, some of the other lipid components (e.g., PEG lipids) of various 10 Formulae, described herein may be synthesized as described International Patent Application No. PCT/US2016/000129, filed December 10, 2016, entitled “Compositions and Methods for Delivery of Therapeutic Agents,” which is incorporated by reference in its entirety. The lipid component of a lipid nanoparticle composition may include one or more 15 molecules comprising polyethylene glycol, such as PEG or PEG-modified lipids. Such species may be alternately referred to as PEGylated lipids. A PEG lipid is a lipid modified with polyethylene glycol. A PEG lipid may be selected from the non-limiting group including PEG-modified phosphatidylethanolamines, PEG-modified phosphatidic acids, PEG-modified ceramides, PEG-modified dialkylamines, PEG-modified 20 diacylglycerols, PEG-modified dialkylglycerols, and mixtures thereof. For example, a PEG lipid may be PEG-c-DOMG, PEG-DMG, PEG-DLPE, PEG-DMPE, PEG-DPPC, or a PEG-DSPE lipid. In some embodiments the PEG-modified lipids are a modified form of PEG- DMG. PEG-DMG has the following structure: 25 , ent invention can be PEGylated lipids described in International Publication No. WO2012099755, the contents of which 158 Attorney Docket No.: 45817-0177WO1 / MTX980.20 is herein incorporated by reference in its entirety. Any of these exemplary PEG lipids described herein may be modified to comprise a hydroxyl group on the PEG chain. In certain embodiments, the PEG lipid is a PEG-OH lipid. As generally defined herein, a “PEG-OH lipid” (also referred to herein as “hydroxy-PEGylated lipid”) is a PEGylated 5 lipid having one or more hydroxyl (–OH) groups on the lipid. In certain embodiments, the PEG-OH lipid includes one or more hydroxyl groups on the PEG chain. In certain embodiments, a PEG-OH or hydroxy-PEGylated lipid comprises an –OH group at the terminus of the PEG chain. Each possibility represents a separate embodiment of the present disclosure. 10 In certain embodiments, a PEG lipid useful in the present invention is a compound of Formula (V). Provided herein are compounds of Formula (V): (V), or salt R3 is –ORO; 15 RO is hydrogen, optionally substituted alkyl, or an oxygen protecting group; r is an integer between 1 and 100, inclusive; L1 is optionally substituted C1-10 alkylene, wherein at least one methylene of the optionally substituted C1-10 alkylene is independently replaced with optionally substituted carbocyclylene, optionally substituted heterocyclylene, optionally substituted20 arylene, optionally substituted heteroarylene, O, N(RN), S, C(O), C(O)N(RN), - NRNC(O), C(O)O, OC(O), OC(O)O, OC(O)N(RN), NRNC(O)O, or NRNC(O)N(RN); D is a moiety obtained by click chemistry or a moiety cleavable under physiological conditions; m is 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10; 25 A is of the Formula: ; each instance of L2 ionally substituted C1-6 alkylene, wherein one methylene unit of the optionally substituted C1-6 alkylene is optionally 159 Attorney Docket No.: 45817-0177WO1 / MTX980.20 replaced with O, N(RN), S, C(O), C(O)N(RN), NRNC(O), C(O)O, OC(O), OC(O)O, - OC(O)N(RN), NRNC(O)O, or NRNC(O)N(RN); each instance of R2 is independently optionally substituted C1-30 alkyl, optionally substituted C1-30 alkenyl, or optionally substituted C1-30 alkynyl; optionally wherein 5 one or more methylene units of R2 are independently replaced with optionally substituted carbocyclylene, optionally substituted heterocyclylene, optionally substituted arylene, optionally substituted heteroarylene, N(RN), O, S, C(O), C(O)N(RN), - NRNC(O), NRNC(O)N(RN), C(O)O, OC(O), OC(O)O, OC(O)N(RN), NRNC(O)O, - C(O)S, SC(O), C(=NRN), C(=NRN)N(RN), NRNC(=NRN), NRNC(=NRN)N(RN), - 10 C(S), C(S)N(RN), NRNC(S), NRNC(S)N(RN), S(O) , OS(O), S(O)O, OS(O)O, OS(O)2, S(O)2O, OS(O)2O, N(RN)S(O), S(O)N(RN), N(RN)S(O)N(RN), OS(O)N(RN), - N(RN)S(O)O, S(O)2, N(RN)S(O)2, S(O)2N(RN), N(RN)S(O)2N(RN), OS(O)2N(RN), or N(RN)S(O)2O; each instance of RN is independently hydrogen, optionally substituted alkyl, or a nitrogen 15 protecting group; Ring B is optionally substituted carbocyclyl, optionally substituted heterocyclyl, optionally substituted aryl, or optionally substituted heteroaryl; and p is 1 or 2. In certain embodiments, the compound of Formula (V) is a PEG-OH lipid (i.e., 20 R3 is –ORO, and RO is hydrogen). In certain embodiments, the compound of Formula (V) is of Formula (V-OH): (V-OH), or a sa e eo . In certain embodiments, a PEG lipid useful in the present invention is a 25 PEGylated fatty acid. In certain embodiments, a PEG lipid useful in the present invention is a compound of Formula (VI). Provided herein are compounds of Formula (VI): 60 Attorney Docket No.: 45817-0177WO1 / MTX980.20 or a salts thereof, wherein: R3 is–ORO; RO is hydrogen, optionally substituted alkyl or an oxygen protecting group; r is an integer between 1 and 100, inclusive; 5 R5 is optionally substituted C10-40 alkyl, optionally substituted C10-40 alkenyl, or optionally substituted C10-40 alkynyl; and optionally one or more methylene groups of R5 are replaced with optionally substituted carbocyclylene, optionally substituted heterocyclylene, optionally substituted arylene, optionally substituted heteroarylene, - N(RN), O, S, C(O), C(O)N(RN), NRNC(O), NRNC(O)N(RN), C(O)O, OC(O), OC(O)O, 10 OC(O)N(RN), NRNC(O)O, C(O)S, SC(O), C(=NRN), C(=NRN)N(RN), NRNC(=NRN), NRNC(=NRN)N(RN), C(S), C(S)N(RN), NRNC(S), NRNC(S)N(RN), S(O), OS(O), - S(O)O, OS(O)O, OS(O)2, S(O)2O, OS(O)2O, N(RN)S(O), S(O)N(RN), - N(RN)S(O)N(RN), OS(O)N(RN), N(RN)S(O)O, S(O)2, N(RN)S(O)2, S(O)2N(RN), - N(RN)S(O)2N(RN), OS(O)2N(RN), or N(RN)S(O)2O; and 15 each instance of RN is independently hydrogen, optionally substituted alkyl, or a nitrogen protecting group. In certain embodiments, the compound of Formula (VI) is of Formula (VI-OH): (VI-OH), or a sal . e embodiments, r is 45. 20 In yet other embodiments the compound of Formula (VI) is: . . In one embodiment, the compound of Formula (VI) is 25 Attorney Docket No.: 45817-0177WO1 / MTX980.20 In some aspects, the lipid composition of the pharmaceutical compositions disclosed herein does not comprise a PEG-lipid. In some embodiments, the PEG-lipids may be one or more of the PEG lipids described in U.S. Application No.62/520,530. 5 In some embodiments, a PEG lipid of the invention comprises a PEG-modified phosphatidylethanolamine, a PEG-modified phosphatidic acid, a PEG-modified ceramide, a PEG-modified dialkylamine, a PEG-modified diacylglycerol, a PEG- modified dialkylglycerol, and mixtures thereof. In some embodiments, the PEG- modified lipid is PEG-DMG, PEG-c-DOMG (also referred to as PEG-DOMG), PEG- 10 DSG and/or PEG-DPG. In some embodiments, a LNP of the invention comprises an ionizable cationic lipid of any of Formula I, II or III, a phospholipid comprising DSPC, a structural lipid, and a PEG lipid comprising PEG-DMG. In some embodiments, a LNP of the invention comprises an ionizable cationic 15 lipid of any of Formula I, II or III, a phospholipid comprising DSPC, a structural lipid, and a PEG lipid comprising a compound having Formula VI. In some embodiments, a LNP of the invention comprises an ionizable cationic lipid of Formula I, II or III, a phospholipid comprising a compound having Formula IV, a structural lipid, and the PEG lipid comprising a compound having Formula V or VI. 20 In some embodiments, a LNP of the invention comprises an ionizable cationic lipid of Formula I, II or III, a phospholipid comprising a compound having Formula IV, a structural lipid, and the PEG lipid comprising a compound having Formula V or VI. In some embodiments, a LNP of the invention comprises an ionizable cationic lipid of Formula I, II or III, a phospholipid having Formula IV, a structural lipid, and a 25 PEG lipid comprising a compound having Formula VI. In some embodiments, a LNP of the invention comprises an ionizable cationic lipid of 162 Attorney Docket No.: 45817-0177WO1 / MTX980.20 , In some embodiments, a LNP of the invention comprises an ionizable cationic lipid of , In some embodiments, a LNP of the invention comprises an ionizable cationic lipid of , 10 lipid comprising cholesterol, and a PEG lipid comprising a compound having Formula VI. In some embodiments, a LNP of the invention comprises an ionizable cationic lipid of 15 g , g ol, and a PEG lipid comprising a compound having Formula VI. 163 Attorney Docket No.: 45817-0177WO1 / MTX980.20 In some embodiments, a LNP of the invention comprises an ionizable cationic lipid of , , , a PEG 5 lipid comprising a compound having Formula VI. In some embodiments, a LNP of the invention comprises an N:P ratio of from about 2:1 to about 30:1. In some embodiments, a LNP of the invention comprises an N:P ratio of about 6:1. 10 In some embodiments, a LNP of the invention comprises an N:P ratio of about 3:1. In some embodiments, a LNP of the invention comprises a wt/wt ratio of the ionizable cationic lipid component to the RNA of from about 10:1 to about 100:1. In some embodiments, a LNP of the invention comprises a wt/wt ratio of the 15 ionizable cationic lipid component to the RNA of about 20:1. In some embodiments, a LNP of the invention comprises a wt/wt ratio of the ionizable cationic lipid component to the RNA of about 10:1. In some embodiments, a LNP of the invention has a mean diameter from about 50nm to about 150nm. 20 In some embodiments, a LNP of the invention has a mean diameter from about 70nm to about 120nm. As used herein, the term "alkyl", "alkyl group", or "alkylene" means a linear or branched, saturated hydrocarbon including one or more carbon atoms (e.g., one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, 25 sixteen, seventeen, eighteen, nineteen, twenty, or more carbon atoms), which is optionally substituted. The notation "C1-14 alkyl" means an optionally substituted linear 164 Attorney Docket No.: 45817-0177WO1 / MTX980.20 or branched, saturated hydrocarbon including 1-14 carbon atoms. Unless otherwise specified, an alkyl group described herein refers to both unsubstituted and substituted alkyl groups. As used herein, the term "alkenyl", "alkenyl group", or "alkenylene" means a 5 linear or branched hydrocarbon including two or more carbon atoms (e.g., two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, nineteen, twenty, or more carbon atoms) and at least one double bond, which is optionally substituted. The notation "C2-14 alkenyl" means an optionally substituted linear or branched hydrocarbon including 2-14 carbon atoms and at least one 10 carbon-carbon double bond. An alkenyl group may include one, two, three, four, or more carbon-carbon double bonds. For example, C18 alkenyl may include one or more double bonds. A C18 alkenyl group including two double bonds may be a linoleyl group. Unless otherwise specified, an alkenyl group described herein refers to both unsubstituted and substituted alkenyl groups. 15 As used herein, the term "alkynyl", "alkynyl group", or "alkynylene" means a linear or branched hydrocarbon including two or more carbon atoms (e.g., two, three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, nineteen, twenty, or more carbon atoms) and at least one carbon- carbon triple bond, which is optionally substituted. The notation "C2-14 alkynyl" means 20 an optionally substituted linear or branched hydrocarbon including 2-14 carbon atoms and at least one carbon-carbon triple bond. An alkynyl group may include one, two, three, four, or more carbon-carbon triple bonds. For example, C18 alkynyl may include one or more carbon-carbon triple bonds. Unless otherwise specified, an alkynyl group described herein refers to both unsubstituted and substituted alkynyl groups. 25 As used herein, the term "carbocycle" or "carbocyclic group" means an optionally substituted mono- or multi-cyclic system including one or more rings of carbon atoms. Rings may be three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, fourteen, fifteen, sixteen, seventeen, eighteen, nineteen, or twenty membered rings. The notation "C3-6 carbocycle" means a carbocycle including a single ring having 3-6 carbon 165 Attorney Docket No.: 45817-0177WO1 / MTX980.20 atoms. Carbocycles may include one or more carbon-carbon double or triple bonds and may be non-aromatic or aromatic (e.g., cycloalkyl or aryl groups). Examples of carbocycles include cyclopropyl, cyclopentyl, cyclohexyl, phenyl, naphthyl, and 1,2 dihydronaphthyl groups. The term "cycloalkyl" as used herein means a non-aromatic 5 carbocycle and may or may not include any double or triple bond. Unless otherwise specified, carbocycles described herein refers to both unsubstituted and substituted carbocycle groups, i.e., optionally substituted carbocycles. As used herein, the term "heterocycle" or "heterocyclic group" means an optionally substituted mono- or multi-cyclic system including one or more rings, where at 10 least one ring includes at least one heteroatom. Heteroatoms may be, for example, nitrogen, oxygen, or sulfur atoms. Rings may be three, four, five, six, seven, eight, nine, ten, eleven, twelve, thirteen, or fourteen membered rings. Heterocycles may include one or more double or triple bonds and may be non-aromatic or aromatic (e.g., heterocycloalkyl or heteroaryl groups). Examples of heterocycles include imidazolyl, 15 imidazolidinyl, oxazolyl, oxazolidinyl, thiazolyl, thiazolidinyl, pyrazolidinyl, pyrazolyl, isoxazolidinyl, isoxazolyl, isothiazolidinyl, isothiazolyl, morpholinyl, pyrrolyl, pyrrolidinyl, furyl, tetrahydrofuryl, thiophenyl, pyridinyl, piperidinyl, quinolyl, and isoquinolyl groups. The term "heterocycloalkyl" as used herein means a non-aromatic heterocycle and may or may not include any double or triple bond. Unless otherwise 20 specified, heterocycles described herein refers to both unsubstituted and substituted heterocycle groups, i.e., optionally substituted heterocycles. As used herein, the term "heteroalkyl", "heteroalkenyl", or "heteroalkynyl", refers respectively to an alkyl, alkenyl, alkynyl group, as defined herein, which further comprises one or more (e.g., 1, 2, 3, or 4) heteroatoms (e.g., oxygen, sulfur, nitrogen, 25 boron, silicon, phosphorus) wherein the one or more heteroatoms is inserted between adjacent carbon atoms within the parent carbon chain and/or one or more heteroatoms is inserted between a carbon atom and the parent molecule, i.e., between the point of attachment. Unless otherwise specified, heteroalkyls, heteroalkenyls, or heteroalkynyls described herein refers to both unsubstituted and substituted heteroalkyls, heteroalkenyls, 166 Attorney Docket No.: 45817-0177WO1 / MTX980.20 or heteroalkynyls, i.e., optionally substituted heteroalkyls, heteroalkenyls, or heteroalkynyls. As used herein, a "biodegradable group" is a group that may facilitate faster metabolism of a lipid in a mammalian entity. A biodegradable group may be selected 5 from the group consisting of, but is not limited to, -C(O)O-, -OC(O)-, -C(O)N(R')-, - N(R')C(O)-, -C(O)-, -C(S)-, -C(S)S-, -SC(S)-, -CH(OH)-, -P(O)(OR')O-, -S(O)2-, an aryl group, and a heteroaryl group. As used herein, an "aryl group" is an optionally substituted carbocyclic group including one or more aromatic rings. Examples of aryl groups include phenyl and naphthyl groups. As used herein, a "heteroaryl group" is an 10 optionally substituted heterocyclic group including one or more aromatic rings. Examples of heteroaryl groups include pyrrolyl, furyl, thiophenyl, imidazolyl, oxazolyl, and thiazolyl. Both aryl and heteroaryl groups may be optionally substituted. For example, M and M' can be selected from the non-limiting group consisting of optionally substituted phenyl, oxazole, and thiazole. In the Formulas herein, M and M' can be 15 independently selected from the list of biodegradable groups above. Unless otherwise specified, aryl or heteroaryl groups described herein refers to both unsubstituted and substituted groups, i.e., optionally substituted aryl or heteroaryl groups. Alkyl, alkenyl, and cyclyl (e.g., carbocyclyl and heterocyclyl) groups may be optionally substituted unless otherwise specified. Optional substituents may be selected 20 from the group consisting of, but are not limited to, a halogen atom (e.g., a chloride, bromide, fluoride, or iodide group), a carboxylic acid (e.g., C(O)OH), an alcohol (e.g., a hydroxyl, OH), an ester (e.g., C(O)OR OC(O)R), an aldehyde (e.g., C(O)H), a carbonyl (e.g., C(O)R, alternatively represented by C=O), an acyl halide (e.g., C(O)X, in which X is a halide selected from bromide, fluoride, chloride, and iodide), a carbonate (e.g., 25 OC(O)OR), an alkoxy (e.g., OR), an acetal (e.g., C(OR)2R"", in which each OR are alkoxy groups that can be the same or different and R"" is an alkyl or alkenyl group), a phosphate (e.g., P(O)43-), a thiol (e.g., SH), a sulfoxide (e.g., S(O)R), a sulfinic acid (e.g., S(O)OH), a sulfonic acid (e.g., S(O)2OH), a thial (e.g., C(S)H), a sulfate (e.g., S(O)42-), a sulfonyl (e.g., S(O)2 ), an amide (e.g., C(O)NR2, or N(R)C(O)R), an azido 167 Attorney Docket No.: 45817-0177WO1 / MTX980.20 (e.g., N3), a nitro (e.g., NO2), a cyano (e.g., CN), an isocyano (e.g., NC), an acyloxy (e.g., OC(O)R), an amino (e.g., NR2, NRH, or NH2), a carbamoyl (e.g., OC(O)NR2, OC(O)NRH, or OC(O)NH2), a sulfonamide (e.g., S(O)2NR2, S(O)2NRH, S(O)2NH2, N(R)S(O)2R, N(H)S(O)2R, N(R)S(O)2H, or N(H)S(O)2H), an alkyl 5 group, an alkenyl group, and a cyclyl (e.g., carbocyclyl or heterocyclyl) group. In any of the preceding, R is an alkyl or alkenyl group, as defined herein. In some embodiments, the substituent groups themselves may be further substituted with, for example, one, two, three, four, five, or six substituents as defined herein. For example, a C1-6 alkyl group may be further substituted with one, two, three, four, five, or six substituents as described 10 herein. Compounds of the disclosure that contain nitrogens can be converted to N-oxides by treatment with an oxidizing agent (e.g., 3-chloroperoxybenzoic acid (mCPBA) and/or hydrogen peroxides) to afford other compounds of the disclosure. Thus, all shown and claimed nitrogen-containing compounds are considered, when allowed by valency and 15 structure, to include both the compound as shown and its N-oxide derivative (which can be designated as N^O or N+-O-). Furthermore, in other instances, the nitrogens in the compounds of the disclosure can be converted to N-hydroxy or N-alkoxy compounds. For example, N-hydroxy compounds can be prepared by oxidation of the parent amine by an oxidizing agent such as m CPBA. All shown and claimed nitrogen-containing 20 compounds are also considered, when allowed by valency and structure, to cover both the compound as shown and its N-hydroxy (i.e., N-OH) and N-alkoxy (i.e., N-OR, wherein R is substituted or unsubstituted C1-C6 alkyl, C1-C6 alkenyl, C1-C6 alkynyl, 3-14- membered carbocycle or 3-14-membered heterocycle) derivatives. 25 Other Lipid Composition Components The lipid composition of a pharmaceutical composition disclosed herein can include one or more components in addition to those described above. For example, the lipid composition can include one or more permeability enhancer molecules, carbohydrates, polymers, surface altering agents (e.g., surfactants), or other components. 168 Attorney Docket No.: 45817-0177WO1 / MTX980.20 For example, a permeability enhancer molecule can be a molecule described by U.S. Patent Application Publication No.2005/0222064. Carbohydrates can include simple sugars (e.g., glucose) and polysaccharides (e.g., glycogen and derivatives and analogs thereof). 5 The ratio between the lipid composition and the polynucleotide range can be from about 10:1 to about 60:1 (wt/wt). In some embodiments, the ratio between the lipid composition and the polynucleotide can be about 10:1, 11:1, 12:1, 13:1, 14:1, 15:1, 16:1, 17:1, 18:1, 19:1, 10 20:1, 21:1, 22:1, 23:1, 24:1, 25:1, 26:1, 27:1, 28:1, 29:1, 30:1, 31:1, 32:1, 33:1, 34:1, 35:1, 36:1, 37:1, 38:1, 39:1, 40:1, 41:1, 42:1, 43:1, 44:1, 45:1, 46:1, 47:1, 48:1, 49:1, 50:1, 51:1, 52:1, 53:1, 54:1, 55:1, 56:1, 57:1, 58:1, 59:1 or 60:1 (wt/wt). In some embodiments, the wt/wt ratio of the lipid composition to the polynucleotide encoding a therapeutic agent is about 20:1 or about 15:1. 15 In some embodiments, the pharmaceutical composition disclosed herein can contain more than one polypeptides. For example, a pharmaceutical composition disclosed herein can contain two or more polynucleotides (e.g., RNA, e.g., mRNA). In one embodiment, the lipid nanoparticles described herein can comprise polynucleotides (e.g., mRNA) in a lipid:polynucleotide weight ratio of 5:1, 10:1, 15:1, 20 20:1, 25:1, 30:1, 35:1, 40:1, 45:1, 50:1, 55:1, 60:1 or 70:1, or a range or any of these ratios such as, but not limited to, 5:1 to about 10:1, from about 5:1 to about 15:1, from about 5:1 to about 20:1, from about 5:1 to about 25:1, from about 5:1 to about 30:1, from about 5:1 to about 35:1, from about 5:1 to about 40:1, from about 5:1 to about 45:1, from about 5:1 to about 50:1, from about 5:1 to about 55:1, from about 5:1 to about 60:1, from 25 about 5:1 to about 70:1, from about 10:1 to about 15:1, from about 10:1 to about 20:1, from about 10:1 to about 25:1, from about 10:1 to about 30:1, from about 10:1 to about 35:1, from about 10:1 to about 40:1, from about 10:1 to about 45:1, from about 10:1 to about 50:1, from about 10:1 to about 55:1, from about 10:1 to about 60:1, from about 10:1 to about 70:1, from about 15:1 to about 20:1, from about 15:1 to about 25:1,from 169 Attorney Docket No.: 45817-0177WO1 / MTX980.20 about 15:1 to about 30:1, from about 15:1 to about 35:1, from about 15:1 to about 40:1, from about 15:1 to about 45:1, from about 15:1 to about 50:1, from about 15:1 to about 55:1, from about 15:1 to about 60:1 or from about 15:1 to about 70:1. In one embodiment, the lipid nanoparticles described herein can comprise the 5 polynucleotide in a concentration from approximately 0.1 mg/ml to 2 mg/ml such as, but not limited to, 0.1 mg/ml, 0.2 mg/ml, 0.3 mg/ml, 0.4 mg/ml, 0.5 mg/ml, 0.6 mg/ml, 0.7 mg/ml, 0.8 mg/ml, 0.9 mg/ml, 1.0 mg/ml, 1.1 mg/ml, 1.2 mg/ml, 1.3 mg/ml, 1.4 mg/ml, 1.5 mg/ml, 1.6 mg/ml, 1.7 mg/ml, 1.8 mg/ml, 1.9 mg/ml, 2.0 mg/ml or greater than 2.0 mg/ml. 10 Nanoparticle Compositions In some embodiments, the pharmaceutical compositions disclosed herein are formulated as lipid nanoparticles (LNP). Accordingly, the present disclosure also provides nanoparticle compositions comprising (i) a lipid composition comprising a 15 delivery agent such as compound as described herein, and (ii) a polynucleotide encoding a GPC3 binding CAR protein. In such nanoparticle composition, the lipid composition disclosed herein acts as a carrier for the polynucleotide encoding a GPC3 binding CAR protein. Nanoparticle compositions are typically sized on the order of micrometers or 20 smaller and can include a lipid bilayer. Nanoparticle compositions encompass lipid nanoparticles (LNPs), liposomes (e.g., lipid vesicles), and lipoplexes. For example, a nanoparticle composition can be a liposome having a lipid bilayer with a diameter of 500 nm or less. Nanoparticle compositions include, for example, lipid nanoparticles (LNPs), 25 liposomes, and lipoplexes. In some embodiments, nanoparticle compositions are vesicles including one or more lipid bilayers. In certain embodiments, a nanoparticle composition includes two or more concentric bilayers separated by aqueous compartments. Lipid bilayers can be functionalized and/or crosslinked to one another. Lipid bilayers can include one or more ligands, proteins, or channels. 170 Attorney Docket No.: 45817-0177WO1 / MTX980.20 In one embodiment, a lipid nanoparticle comprises an ionizable amino lipid, a structural lipid, a phospholipid, and mRNA. In some embodiments, the LNP comprises an ionizable amino lipid, a PEG-modified lipid, a sterol and a structural lipid. In some embodiments, the LNP has a molar ratio of about 40-50% ionizable amino lipid; about 5- 5 15% structural lipid; about 30-45% sterol; and about 1-5% PEG-modified lipid. In certain cases, the LNP comprises Compound II, Compound IV, Compound I, and Cholesterol (e.g., 48 mol% Compound II, 11 mol% Compound IV, 39 mol% cholesterol, and 2 mol% Compound I). In other cases, the LNP comprises Compound II, Compound IV, PEG-DMG, and Cholesterol (e.g., 48 mol% Compound II,11 mol% Compound IV, 10 39.5 mol% cholesterol, and 1.5 mol% PEG-DMG). In some cases, the LNP comprises Compound III, Compound IV, Cholesterol, Compound I, and Compound V (e.g., 39.70 mol% Compound III, 18.70 mol % Compound IV, 34.50 mol % Cholesterol, 3.00 mol % Compound I, and 4.10 mol % Compound V). In some embodiments, the LNP has a polydispersity value of less than 0.4. In 15 some embodiments, the LNP has a net neutral charge at a neutral pH. In some embodiments, the LNP has a mean diameter of 50-150 nm. In some embodiments, the LNP has a mean diameter of 80-100 nm. As generally defined herein, the term “lipid” refers to a small molecule that has hydrophobic or amphiphilic properties. Lipids may be naturally occurring or synthetic. 20 Examples of classes of lipids include, but are not limited to, fats, waxes, sterol-containing metabolites, vitamins, fatty acids, glycerolipids, glycerophospholipids, sphingolipids, saccharolipids, and polyketides, and prenol lipids. In some instances, the amphiphilic properties of some lipids leads them to form liposomes, vesicles, or membranes in aqueous media. 25 In some embodiments, a lipid nanoparticle (LNP) may comprise an ionizable amino lipid. As used herein, the term “ionizable amino lipid” has its ordinary meaning in the art and may refer to a lipid comprising one or more charged moieties. In some embodiments, an ionizable amino lipid may be positively charged or negatively charged. An ionizable amino lipid may be positively charged, in which case it can be referred to as 171 Attorney Docket No.: 45817-0177WO1 / MTX980.20 “cationic lipid”. In certain embodiments, an ionizable amino lipid molecule may comprise an amine group, and can be referred to as an ionizable amino lipid. As used herein, a “charged moiety” is a chemical moiety that carries a formal electronic charge, e.g., monovalent (+1, or -1), divalent (+2, or -2), trivalent (+3, or -3), etc. The charged 5 moiety may be anionic (i.e., negatively charged) or cationic (i.e., positively charged). Examples of positively-charged moieties include amine groups (e.g., primary, secondary, and/or tertiary amines), ammonium groups, pyridinium group, guanidine groups, and imidizolium groups. In a particular embodiment, the charged moieties comprise amine groups. Examples of negatively- charged groups or precursors thereof, include 10 carboxylate groups, sulfonate groups, sulfate groups, phosphonate groups, phosphate groups, hydroxyl groups, and the like. The charge of the charged moiety may vary, in some cases, with the environmental conditions, for example, changes in pH may alter the charge of the moiety, and/or cause the moiety to become charged or uncharged. In general, the charge density of the molecule may be selected as desired. 15 It should be understood that the terms “charged” or “charged moiety” does not refer to a “partial negative charge" or “partial positive charge" on a molecule. The terms “partial negative charge" and “partial positive charge" are given its ordinary meaning in the art. A “partial negative charge" may result when a functional group comprises a bond that becomes polarized such that electron density is pulled toward one atom of the bond, 20 creating a partial negative charge on the atom. Those of ordinary skill in the art will, in general, recognize bonds that can become polarized in this way. The ionizable amino lipid is sometimes referred to in the art as an “ionizable cationic lipid”. In one embodiment, the ionizable amino lipid may have a positively charged hydrophilic head and a hydrophobic tail that are connected via a linker structure. 25 In addition to these, an ionizable amino lipid may also be a lipid including a cyclic amine group. In one embodiment, the ionizable amino lipid may be selected from, but not limited to, an ionizable amino lipid described in International Publication Nos. WO2013086354 and 172 Attorney Docket No.: 45817-0177WO1 / MTX980.20 WO2013116126; the contents of each of which are herein incorporated by reference in their entirety. In yet another embodiment, the ionizable amino lipid may be selected from, but not limited to, Formula CLI-CLXXXXII of US Patent No.7,404,969; each of which is 5 herein incorporated by reference in their entirety. In one embodiment, the lipid may be a cleavable lipid such as those described in International Publication No. WO2012170889, herein incorporated by reference in its entirety. In one embodiment, the lipid may be synthesized by methods known in the art and/or as described in International Publication Nos. WO2013086354; the contents of 10 each of which are herein incorporated by reference in their entirety. Nanoparticle compositions can be characterized by a variety of methods. For example, microscopy (e.g., transmission electron microscopy or scanning electron microscopy) can be used to examine the morphology and size distribution of a nanoparticle composition. Dynamic light scattering or potentiometry (e.g., 15 potentiometric titrations) can be used to measure zeta potentials. Dynamic light scattering can also be utilized to determine particle sizes. Instruments such as the Zetasizer Nano ZS (Malvern Instruments Ltd, Malvern, Worcestershire, UK) can also be used to measure multiple characteristics of a nanoparticle composition, such as particle size, polydispersity index, and zeta potential. 20 The size of the nanoparticles can help counter biological reactions such as, but not limited to, inflammation, or can increase the biological effect of the polynucleotide. As used herein, “size” or “mean size” in the context of nanoparticle compositions refers to the mean diameter of a nanoparticle composition. In one embodiment, the polynucleotide encoding a GPC3 binding CAR protein 25 are formulated in lipid nanoparticles having a diameter from about 10 to about 100 nm such as, but not limited to, about 10 to about 20 nm, about 10 to about 30 nm, about 10 to about 40 nm, about 10 to about 50 nm, about 10 to about 60 nm, about 10 to about 70 nm, about 10 to about 80 nm, about 10 to about 90 nm, about 20 to about 30 nm, about 20 to about 40 nm, about 20 to about 50 nm, about 20 to about 60 nm, about 20 to about 70 nm, 173 Attorney Docket No.: 45817-0177WO1 / MTX980.20 about 20 to about 80 nm, about 20 to about 90 nm, about 20 to about 100 nm, about 30 to about 40 nm, about 30 to about 50 nm, about 30 to about 60 nm, about 30 to about 70 nm, about 30 to about 80 nm, about 30 to about 90 nm, about 30 to about 100 nm, about 40 to about 50 nm, about 40 to about 60 nm, about 40 to about 70 nm, about 40 to about 80 nm, 5 about 40 to about 90 nm, about 40 to about 100 nm, about 50 to about 60 nm, about 50 to about 70 nm, about 50 to about 80 nm, about 50 to about 90 nm, about 50 to about 100 nm, about 60 to about 70 nm, about 60 to about 80 nm, about 60 to about 90 nm, about 60 to about 100 nm, about 70 to about 80 nm, about 70 to about 90 nm, about 70 to about 100 nm, about 80 to about 90 nm, about 80 to about 100 nm and/or about 90 to about 100 10 nm. In one embodiment, the nanoparticles have a diameter from about 10 to 500 nm. In one embodiment, the nanoparticle has a diameter greater than 100 nm, greater than 150 nm, greater than 200 nm, greater than 250 nm, greater than 300 nm, greater than 350 nm, greater than 400 nm, greater than 450 nm, greater than 500 nm, greater than 550 nm, 15 greater than 600 nm, greater than 650 nm, greater than 700 nm, greater than 750 nm, greater than 800 nm, greater than 850 nm, greater than 900 nm, greater than 950 nm or greater than 1000 nm. In some embodiments, the largest dimension of a nanoparticle composition is 1 µm or shorter (e.g., 1 µm, 900 nm, 800 nm, 700 nm, 600 nm, 500 nm, 400 nm, 300 nm, 200 nm, 20 175 nm, 150 nm, 125 nm, 100 nm, 75 nm, 50 nm, or shorter). A nanoparticle composition can be relatively homogenous. A polydispersity index can be used to indicate the homogeneity of a nanoparticle composition, e.g., the particle size distribution of the nanoparticle composition. A small (e.g., less than 0.3) polydispersity index generally indicates a narrow particle size distribution. A 25 nanoparticle composition can have a polydispersity index from about 0 to about 0.25, such as 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, or 0.25. In some embodiments, the polydispersity index of a nanoparticle composition disclosed herein can be from about 0.10 to about 0.20. 174 Attorney Docket No.: 45817-0177WO1 / MTX980.20 The zeta potential of a nanoparticle composition can be used to indicate the electrokinetic potential of the composition. For example, the zeta potential can describe the surface charge of a nanoparticle composition. Nanoparticle compositions with relatively low charges, positive or negative, are generally desirable, as more highly 5 charged species can interact undesirably with cells, tissues, and other elements in the body. In some embodiments, the zeta potential of a nanoparticle composition disclosed herein can be from about -10 mV to about +20 mV, from about -10 mV to about +15 mV, from about 10 mV to about +10 mV, from about -10 mV to about +5 mV, from about - 10 mV to about 0 mV, from about -10 mV to about -5 mV, from about -5 mV to about 10 +20 mV, from about -5 mV to about +15 mV, from about -5 mV to about +10 mV, from about -5 mV to about +5 mV, from about -5 mV to about 0 mV, from about 0 mV to about +20 mV, from about 0 mV to about +15 mV, from about 0 mV to about +10 mV, from about 0 mV to about +5 mV, from about +5 mV to about +20 mV, from about +5 mV to about +15 mV, or from about +5 mV to about +10 mV. 15 In some embodiments, the zeta potential of the lipid nanoparticles can be from about 0 mV to about 100 mV, from about 0 mV to about 90 mV, from about 0 mV to about 80 mV, from about 0 mV to about 70 mV, from about 0 mV to about 60 mV, from about 0 mV to about 50 mV, from about 0 mV to about 40 mV, from about 0 mV to about 30 mV, from about 0 mV to about 20 mV, from about 0 mV to about 10 mV, from 20 about 10 mV to about 100 mV, from about 10 mV to about 90 mV, from about 10 mV to about 80 mV, from about 10 mV to about 70 mV, from about 10 mV to about 60 mV, from about 10 mV to about 50 mV, from about 10 mV to about 40 mV, from about 10 mV to about 30 mV, from about 10 mV to about 20 mV, from about 20 mV to about 100 mV, from about 20 mV to about 90 mV, from about 20 mV to about 80 mV, from about 25 20 mV to about 70 mV, from about 20 mV to about 60 mV, from about 20 mV to about 50 mV, from about 20 mV to about 40 mV, from about 20 mV to about 30 mV, from about 30 mV to about 100 mV, from about 30 mV to about 90 mV, from about 30 mV to about 80 mV, from about 30 mV to about 70 mV, from about 30 mV to about 60 mV, from about 30 mV to about 50 mV, from about 30 mV to about 40 mV, from about 40 175 Attorney Docket No.: 45817-0177WO1 / MTX980.20 mV to about 100 mV, from about 40 mV to about 90 mV, from about 40 mV to about 80 mV, from about 40 mV to about 70 mV, from about 40 mV to about 60 mV, and from about 40 mV to about 50 mV. In some embodiments, the zeta potential of the lipid nanoparticles can be from about 10 mV to about 50 mV, from about 15 mV to about 45 5 mV, from about 20 mV to about 40 mV, and from about 25 mV to about 35 mV. In some embodiments, the zeta potential of the lipid nanoparticles can be about 10 mV, about 20 mV, about 30 mV, about 40 mV, about 50 mV, about 60 mV, about 70 mV, about 80 mV, about 90 mV, and about 100 mV. The amount of a polynucleotide present in a pharmaceutical composition 10 disclosed herein can depend on multiple factors such as the size of the polynucleotide, desired target and/or application, or other properties of the nanoparticle composition as well as on the properties of the polynucleotide. For example, the amount of an mRNA useful in a nanoparticle composition can depend on the size (expressed as length, or molecular mass), sequence, and other 15 characteristics of the mRNA. The relative amounts of a polynucleotide in a nanoparticle composition can also vary. The relative amounts of the lipid composition and the polynucleotide present in a lipid nanoparticle composition of the present disclosure can be optimized according to considerations of efficacy and tolerability. For compositions including an mRNA as a 20 polynucleotide, the N:P ratio can serve as a useful metric. As the N:P ratio of a nanoparticle composition controls both expression and tolerability, nanoparticle compositions with low N:P ratios and strong expression are desirable. N:P ratios vary according to the ratio of lipids to RNA in a nanoparticle composition. 25 In general, a lower N:P ratio is preferred. The one or more RNA, lipids, and amounts thereof can be selected to provide an N:P ratio from about 2:1 to about 30:1, such as 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 12:1, 14:1, 16:1, 18:1, 20:1, 22:1, 24:1, 26:1, 28:1, or 30:1. In certain embodiments, the N:P ratio can be from about 2:1 to about 8:1. In other embodiments, the N:P ratio is from about 5:1 to about 8:1. In certain embodiments, 176 Attorney Docket No.: 45817-0177WO1 / MTX980.20 the N:P ratio is between 5:1 and 6:1. In one specific aspect, the N:P ratio is about is about 5.67:1. In addition to providing nanoparticle compositions, the present disclosure also provides methods of producing lipid nanoparticles formulated with a polynucleotide (e.g., 5 mRNA). Such method comprises using any of the pharmaceutical compositions disclosed herein and producing lipid nanoparticles in accordance with methods of production of lipid nanoparticles known in the art. See, e.g., Wang et al. (2015) “Delivery of oligonucleotides with lipid nanoparticles” Adv. Drug Deliv. Rev.87:68-80; Silva et al. (2015) “Delivery Systems for Biopharmaceuticals. Part I: Nanoparticles and 10 Microparticles” Curr. Pharm. Technol.16: 940-954; Naseri et al. (2015) “Solid Lipid Nanoparticles and Nanostructured Lipid Carriers: Structure, Preparation and Application” Adv. Pharm. Bull.5:305-13; Silva et al. (2015) “Lipid nanoparticles for the delivery of biopharmaceuticals” Curr. Pharm. Biotechnol.16:291-302, and references cited therein. mRNA-Lipid Adducts 15 It has been determined that certain ionizable lipids are susceptible to the formation of lipid-polynucleotide adducts. In particular, ionizable lipids that comprise a tertiary amine group may decompose into one or both of a secondary amine and a reactive aldehyde species capable of interacting with polynucleotides (such as mRNA) to form an ionizable lipid-polynucleotide adduct impurity that can be detected by reverse 20 phase ion pair chromatography (RP-IP HPLC). For example, oxidation of the tertiary amine may lead to N-oxide formation that can undergo acid/base-catalyzed hydrolysis at the amine to generate aldehydes and secondary amines which may form adducts with mRNA. Thus, in some aspects, the ionizable lipid-polynucleotide adduct impurity is an aldehyde-mRNA adduct impurity. 25 It also has been determined that such adducts may disrupt mRNA translation and impact the activity of lipid nanoparticle (LNP) formulated mRNA products. Thus, it can be advantageous to prepare and use LNP compositions with a reduced content of ionizable lipid-polynucleotide adduct impurity, such as wherein less than about 20%, less than about 10%, less than about 5%, or less than about 1%, of the mRNA is in the form 177 Attorney Docket No.: 45817-0177WO1 / MTX980.20 of ionizable lipid-polynucleotide adduct impurity, as may be measured by RP-IP HPLC. Thus, in accordance with some aspects, an LNP composition is provided wherein less than about 10%, less than about 5%, or less than about 1%, of the mRNA is in the form of ionizable lipid-polynucleotide adduct impurity, including less than 10%, less than 5%, 5 or less than 1%, as may be measured by RP-IP HPLC. In some aspects, an amount of lipid aldehydes in the composition is less than about 50 ppm, including less than 50 ppm. Additionally or alternatively, in some aspects an amount of N-oxide compounds in the composition is less than about 50 ppm, including less than 50 ppm. Additionally or alternatively, in some aspects an amount of 10 transition metals, such as Fe, in the composition is less than about 50 ppm, including less than 50 ppm. Additionally or alternatively, in some aspects an amount of alkyl halide compounds in the composition is less than about 50 ppm, including less than 50 ppm. Additionally or alternatively, in some aspects an amount of anhydride compounds in the composition is less than about 50 ppm, including less than 50 ppm. Additionally or 15 alternatively, in some aspects an amount of ketone compounds in the composition is less than about 50 ppm, including less than 50 ppm. Additionally or alternatively, in some aspects an amount of conjugated diene compounds in the composition is less than about 50 ppm, including less than 50 ppm. In some aspects, the composition is stable against the formation of ionizable lipid-20 polynucleotide adduct impurity. In some aspects, an amount of ionizable lipid- polynucleotide adduct impurity in the composition increases at an average rate of less than about 2% per day when stored at a temperature of about 25 °C or below, including at an average rate of less than 2% per day. In some aspects, an amount of ionizable lipid- polynucleotide adduct impurity in the composition increases at an average rate of less 25 than about 0.5% per day when stored at a temperature of about 5 °C or below, including at an average rate of less than 0.5% per day. In some aspects, an amount of ionizable lipid-polynucleotide adduct impurity in the composition increases at an average rate of less than about 0.5% per day when stored at a refrigerated temperature, optionally wherein the refrigerated temperature is about 5 °C. 178 Attorney Docket No.: 45817-0177WO1 / MTX980.20 Lipid vehicle (e.g., LNP) compositions with a reduced content of ionizable lipid- polynucleotide adduct impurity can be prepared by methods that inhibit formation of one or both of N-oxides and aldehydes. Such methods may comprise treating a composition comprising an ionizable lipid comprising a tertiary amine group to inhibit formation of 5 one or both of N-oxides and aldehydes, such as by treating the composition with a reducing agent; treating the composition with a chelating agent; adjusting the pH of the composition; adjusting the temperature of the composition; and adjusting the buffer in the composition. Such methods may comprise, prior to combining the ionizable lipid with a polynucleotide, one or more of treating the ionizable lipid with a scavenging agent; 10 treating the ionizable lipid with a reductive treatment agent; treating the ionizable lipid with a reducing agent; treating the ionizable lipid with a chelating agent; treating the polynucleotide with a reducing agent; and treating the polynucleotide with a chelating agent. In accordance with any of the foregoing, the scavenging agent, reductive 15 treatment agent, and/or reducing agent may be an agent that reacts with aldehyde, ketone, anhydride and/or diene compounds. A scavenging agent may comprise one or more selected from (O-(2,3,4,5,6-Pentafluorobenzyl)hydroxylamine hydrochloride) (PFBHA), methoxyamine (e.g., methoxyamine hydrochloride), benzyloxyamine (e.g., benzyloxyamine hydrochloride), ethoxyamine (e.g., ethoxyamine hydrochloride), 4-[2- 20 (aminooxy)ethyl]morpholine dihydrochloride, butoxyamine (e.g., tert-butoxyamine hydrochloride), 4-Dimethylaminopyridine (DMAP), 1,4-diazabicyclo[2.2.2]octane (DABCO), Triethylamine (TEA), Piperidine 4-carboxylate (BPPC), and combinations thereof. A reductive treatment agent may comprise a boron compound (e.g., sodium borohydride and/or bis(pinacolato)diboron). A reductive treatment agent may comprise a 25 boron compound, such as one or both of sodium borohydride and bis(pinacolato)diboron). A chelating agent may comprise immobilized iminodiacetic acid. A reducing agent may comprise an immobilized reducing agent, such as immobilized diphenylphosphine on silica (Si-DPP), immobilized thiol on agarose (Ag- Thiol), immobilized cysteine on silica (Si-Cysteine), immobilized thiol on silica (Si- 179 Attorney Docket No.: 45817-0177WO1 / MTX980.20 Thiol), or a combination thereof. A reducing agent may comprise a free reducing agent, such as potassium metabisulfite, sodium thioglycolate, tris(2-carboxyethyl)phosphine (TCEP), sodium thiosulfate, N-acetyl cysteine, glutathione, dithiothreitol (DTT), cystamine, dithioerythritol (DTE), dichlorodiphenyltrichloroethane (DDT), 5 homocysteine, lipoic acid, or a combination thereof. In accordance with any of the foregoing, the pH may be, or adjusted to be, a pH of from about 7 to about 9. In accordance with any of the foregoing, a buffer may be selected from sodium phosphate, sodium citrate, sodium succinate, histidine, histidine-HCl, sodium malate, 10 sodium carbonate, and TRIS (tris(hydroxymethyl)aminomethane). In accordance with any of the foregoing, a buffer may be TRIS and may be, or adjusted to be, from about 20 mM to about 150 mM TRIS. In accordance with any of the foregoing, the temperature of the composition may be, or adjusted to be, 25 ⁰C or less. 15 The composition may also comprise a free reducing agent or antioxidant. Conjugates In some embodiments, the compositions or formulations of the present disclosure comprise the polynucleotides described herein (e.g., a polynucleotide comprising a 20 nucleotide sequence encoding a GPC3 binding CAR protein) that is covalently linked to a carrier or targeting group, or including two encoding regions that together produce a fusion protein (e.g., bearing a targeting group and therapeutic protein or peptide) as a conjugate. The conjugate can be a peptide that selectively directs the nanoparticle to neurons in a tissue or organism, or assists in crossing the blood-brain barrier. 25 The conjugates include a naturally occurring substance, such as a protein (e.g., human serum albumin (HSA), low-density lipoprotein (LDL), high-density lipoprotein (HDL), or globulin); an carbohydrate (e.g., a dextran, pullulan, chitin, chitosan, inulin, cyclodextrin or hyaluronic acid); or a lipid. The ligand can also be a recombinant or synthetic molecule, such as a synthetic polymer, e.g., a synthetic polyamino acid, an 180 Attorney Docket No.: 45817-0177WO1 / MTX980.20 oligonucleotide (e.g., an aptamer). Examples of polyamino acids include polyamino acid is a polylysine (PLL), poly L-aspartic acid, poly L-glutamic acid, styrene-maleic acid anhydride copolymer, poly(L-lactide-co-glycolied) copolymer, divinyl ether-maleic anhydride copolymer, N-(2-hydroxypropyl)methacrylamide copolymer (HMPA), 5 polyethylene glycol (PEG), polyvinyl alcohol (PVA), polyurethane, poly(2-ethylacryllic acid), N-isopropylacrylamide polymers, or polyphosphazine. Example of polyamines include: polyethylenimine, polylysine (PLL), spermine, spermidine, polyamine, pseudopeptide-polyamine, peptidomimetic polyamine, dendrimer polyamine, arginine, amidine, protamine, cationic lipid, cationic porphyrin, quaternary salt of a polyamine, or 10 an alpha helical peptide. In some embodiments, the conjugate can function as a carrier for the polynucleotide disclosed herein. The conjugate can comprise a cationic polymer such as, but not limited to, polyamine, polylysine, polyalkylenimine, and polyethylenimine that can be grafted to with poly(ethylene glycol). Exemplary conjugates and their preparations 15 are described in U.S. Pat. No.6,586,524 and U.S. Pub. No. US20130211249, each of which herein is incorporated by reference in its entirety. The conjugates can also include targeting groups, e.g., a cell or tissue targeting agent, e.g., a lectin, glycoprotein, lipid or protein, e.g., an antibody, that binds to a specified cell type such as a kidney cell. A targeting group can be a thyrotropin, 20 melanotropin, lectin, glycoprotein, surfactant protein A, Mucin carbohydrate, multivalent lactose, multivalent galactose, N-acetyl-galactosamine, N-acetyl-glucosamine multivalent mannose, multivalent fucose, glycosylated polyaminoacids, multivalent galactose, transferrin, bisphosphonate, polyglutamate, polyaspartate, a lipid, cholesterol, a steroid, bile acid, folate, vitamin B12, biotin, an RGD peptide, an RGD peptide mimetic or an 25 aptamer. Targeting groups can be proteins, e.g., glycoproteins, or peptides, e.g., molecules having a specific affinity for a co-ligand, or antibodies e.g., an antibody, that binds to a specified cell type such as an endothelial cell or bone cell. Targeting groups can also include hormones and hormone receptors. They can also include non-peptidic species, 181 Attorney Docket No.: 45817-0177WO1 / MTX980.20 such as lipids, lectins, carbohydrates, vitamins, cofactors, multivalent lactose, multivalent galactose, N-acetyl-galactosamine, N-acetyl-glucosamine multivalent mannose, multivalent frucose, or aptamers. The ligand can be, for example, a lipopolysaccharide, or an activator of p38 MAP kinase. 5 The targeting group can be any ligand that is capable of targeting a specific receptor. Examples include, without limitation, folate, GalNAc, galactose, mannose, mannose-6P, aptamers, integrin receptor ligands, chemokine receptor ligands, transferrin, biotin, serotonin receptor ligands, PSMA, endothelin, GCPII, somatostatin, LDL, and HDL ligands. In particular embodiments, the targeting group is an aptamer. The aptamer can be10 unmodified or have any combination of modifications disclosed herein. As a non- limiting example, the targeting group can be a glutathione receptor (GR)-binding conjugate for targeted delivery across the blood-central nervous system barrier as described in, e.g., U.S. Pub. No. US2013021661012 (herein incorporated by reference in its entirety). 15 In some embodiments, the conjugate can be a synergistic biomolecule-polymer conjugate, which comprises a long-acting continuous-release system to provide a greater therapeutic efficacy. The synergistic biomolecule-polymer conjugate can be those described in U.S. Pub. No. US20130195799. In some embodiments, the conjugate can be an aptamer conjugate as described in Intl. Pat. Pub. No. WO2012040524. In some 20 embodiments, the conjugate can be an amine containing polymer conjugate as described in U.S. Pat. No.8,507,653. Each of the references is herein incorporated by reference in its entirety. In some embodiments, the polynucleotides can be conjugated to SMARTT POLYMER TECHNOLOGY® (PHASERX®, Inc. Seattle, WA). In some embodiments, the polynucleotides described herein are covalently 25 conjugated to a cell penetrating polypeptide, which can also include a signal sequence or a targeting sequence. The conjugates can be designed to have increased stability, and/or increased cell transfection; and/or altered the biodistribution (e.g., targeted to specific tissues or cell types). 182 Attorney Docket No.: 45817-0177WO1 / MTX980.20 In some embodiments, the polynucleotides described herein can be conjugated to an agent to enhance delivery. In some embodiments, the agent can be a monomer or polymer such as a targeting monomer or a polymer having targeting blocks as described in Intl. Pub. No. WO2011062965. In some embodiments, the agent can be a transport 5 agent covalently coupled to a polynucleotide as described in, e.g., U.S. Pat. Nos. 6,835.393 and 7,374,778. In some embodiments, the agent can be a membrane barrier transport enhancing agent such as those described in U.S. Pat. Nos.7,737,108 and 8,003,129. Each of the references is herein incorporated by reference in its entirety. 10 Methods of Use The polypeptides, polynucleotides, pharmaceutical compositions, and formulations described above are used in the preparation, manufacture and therapeutic use of compositions to treat a GPC3 related or associated disorder. In some cases, the subject expresses abnormal levels of GPC3 (e.g., increased relative to a subject without 15 the disease). In some cases, the polypeptides, polynucleotides, pharmaceutical compositions, and formulations described above are used for the treatment of a GPC3+ cancer or tumor in a subject in need thereof. In one instance, the GPC3+ cancer or tumor is a liver cancer such as Hepatocellular Carcinoma (HCC). In one case the HCC is relapsed or refractory 20 HCC. In another instance, the GPC3+ cancer or tumor is a pancreatic cancer. In one case, the pancreatic cancer is pancreatic ductal adenocarcinoma (PDAC). In another instance, the GPC3+ cancer or tumor is a lung cancer. In one case, the lung cancer is a squamous cell lung cancer. In another case, the lung cancer is lung squamous cell carcinoma (LSCC). In other instances, the GPC3+ cancer or tumor is a breast cancer, a skin cancer, an 25 ovarian cancer, a thyroid cancer, or a urothelial cancer. In yet other instances, the GPC3+ cancer or tumor is a head and neck squamous cell cancer, a melanoma, a Merkel cell carcinoma (MCC), an ovarian clear cell carcinoma (OCCC), a urothelial carcinoma, a salivary gland tumor, a glioblastoma, a pediatric solid embryonal tumor, a germ cell tumors (e.g., a yolk sac tumor, a choriocarcinoma), Wilms tumor, a rhabdomyosarcoma 30 (RMS), or a pediatric sarcoma. 183 Attorney Docket No.: 45817-0177WO1 / MTX980.20 A subject in need of treatment is administered a therapeutically effective amount of a polypeptide, a polynucleotide, a pharmaceutical composition, or a formulation described above. In some instances, the subject is a human. In certain instances, the subject is administered the therapeutically effective amount intravenously. Repeated IV 5 infusions are encompassed by this disclosure. In one instance, a therapeutically effective amount of an mRNA encoding a GPC3 binding CAR described above is administered by repeated IV infusions to a subject in need thereof (e.g., a human subject). In some instances, the mRNA comprises the sequence set forth in SEQ ID NO: 8 or 9 wherein all U’s in these nucleic acid sequences 10 are N1-methylpseudouracil. In some instances, the mRNA further comprises a 5’UTR with the sequence of SEQ ID NO: 7 and a 3’UTR with a sequence set forth in any one of SEQ ID NOs.: 10-12. In certain cases, the mRNA has a 5’ terminal cap that comprises m7Gp-ppGm-A. In some cases, the mRNA comprises a poly A tail set forth in any one of SEQ ID NO: 117 or 13. In some instances, the mRNA is formulated in a LNP. In some 15 cases, the LNP comprises an ionizable amino lipid, a structural lipid, a phospholipid, and a polyethylene glycol (PEG)-modified lipid. In some cases, the LNP comprises Compound II, Compound I, Compound IV, and Cholesterol. In certain cases, the LNP comprises Compound II, PEG-DMG, Compound IV, and Cholesterol. In other cases, the LNP comprises Compound III, Compound I, Compound V, and Cholesterol. In other 20 cases, the LNP comprises Compound III, Compound IV, Cholesterol, Compound I, and Compound V. In one case, the human subject has a liver cancer (e.g., HCC). In one case, the HCC is relapsed or refractory HCC. In some cases, the treatment involves administering a second agent. The second 25 agent may be a checkpoint inhibitor and/or an accessory molecule. In some cases, the checkpoint inhibitor is a PD-1 inhibitor. In some cases, the checkpoint inhibitor is a PD- LI inhibitor. In certain cases, the checkpoint inhibitor is a CTLA-4 inhibitor. In other cases, the checkpoint inhibitor is a LAG-3 inhibitor. In yet other cases, the checkpoint inhibitor is a CISH inhibitor. In certain cases, the accessory molecule is CD40L. The 184 Attorney Docket No.: 45817-0177WO1 / MTX980.20 second agent may be administered as a protein or as an mRNA (e.g., formulated in a LNP and in some cases co-formulated with the mRNA encoding the GPC3 CAR protein). In some cases, the treatment involves administering a polypeptide, a polynucleotide, a pharmaceutical composition, or a formulation described above once 5 every week, twice every week, three times every week, once every two weeks, once every three weeks, or once every four weeks. 185

A CGG CGGGCCCG GGGCG AG GCUU CC CGGUCGGG UCGC C CCGG C GAUUAGCG CCUC GGAU ACGCA GC CC CGC UAGCACGC GGC CCG GGC C C G G C G CGUUCCC U CGAG ACGU CC A AACUGCUU UGAU CAA C CCG AC UA ⁰ UAG GUCUGCC CAUA CG C UAG UA GC AUAC GGCC C ₂ ^. UUAA₀ GUCGAUA GC A G GG CGA GC GCG UGAC AA AG AU CCGG AAGA CAAUU GUC CCGUG ACAC AGAC ⁸ ₉ U UG C GGGACAAGAC AC UG G U UGGCGAAUAAA CX U C GAAUAA C GGCCGUT U C GC GUCG UU AC G CGA ^M U _/ UCA UAG CUGC GCGA CA U UCA UU U G G GGUAAC U ₁ CA U ACCGGG A GUUA A GCCAGG UC CUA CA A C G U GO GCG AAGG C GUACUUGU GCG AU UAC U ACAGGCU AC UCCA GCUA AC C C ACU ^W ₇ AUCC G UA AUCCG GG⁷ CGGCUCG C A CUGAC CUAG CGG UCUU U AACA CCCC ₁ ⁰ G - AAA CAU CAGU CCCC CU G AGCU G ⁷ A UCAC AC U AUGCACGACC GGAUCGA ₁ U U G A U A C⁸ ₅ ⁴ _: ^. _o ^N _t ^e _k ^c _o ^{D y} _e ⁿ _r ^ot _t A N CAAUCCU A U C ACCGA CCG O _e ^h U AGCCCGAC C C UAC UUCCGC AG CAAUU UUGU C t ^e AUUCAA CCCGUUGUC UCCCG AUUCUGUGUGU n_{i c )} ⁿ AGUC GUGUC G UCCA CG UGU CCA A GGUUA CCC U _e ( u GCGGUUAUCC U GCGGGUGCGAC s_l ^q GC G UGC CC C U A U G GAC GCUAGAU GCA A AUU C C A CCC C AC i _e GCCG CG AU G GCUGCU mUA CUG UAC mUA CG GUA c ^{S a G} r A _pCGGCCGC CGUAC C₀ pU CGGGAA CGA ^{0 G} _pCGGGAAC UGAGU GCGA CUA AGU GC C₁ ^pCC GA u^l N _p C G l GGGGGCA UAC A C ^A _p GGGC GGUA CAGC GCG a R ^G ₇ G UA C G G- ^G ₇ UUC G UUCGCGAC GGGAG UGG t m AC m U C G A G A C U G G C G m U U G G C C C G G G a^h t^t _n Q a E e S ^D _I O ₀ N ⁰ _{1 2} ⁰ ₂ m ^s i ¹ m ^:l _{) i} Q^{7 2} m ^:l _{) i} Q^{7 ”} ₅ A ^t e _c ^{G u a} r _p ^{p t} E₁ S ^{( 1} _: ^t _c ^{G u a} r _p ^{p t} E₁ S ^{( 1} _: G _“ N ^t y R ^m _{a s} ⁿ _{: o 5} ^p _p A a ^G _{7 y t} l_o ⁿ O ^t 0 ^N _s 0 ⁿ _: ^p _p A G _{y t} O l ^{n N} B m N C G C m P ₁ ^D _{I o} C ₅ G _a C₇ m _{o 0} P⁰ ₁ ^D _I

C AG G CGGUCCCCG C GGCCUUA AGGGCCCGG CG AGGGCCCGG CU CGGUCGGGCGCC CGGUCGGGCG G CCUCAUCAC U CCUCGAUUAGCG CCUCG UUAG G GGGGCACCCUC GGCCACGCGCCG GGCC A C CGC U CAAAAUUUGGC CAGGCG GCCCG CAGGA GGCC G UGCCCGUUGUC UGAA U CUGCUU UGAACGUUGC A CAGA UGCCUC CAGCAA CACAG CAGCAACCAC ⁰ G U U AAU CAU UGU UGCC UCA UGU UGCC U₂ ^. ₀ U ⁸ C ₉ U X GT A ^M A _/ A ₁ U O A^W A ₇ ⁷ G ₁ U ⁰- U ⁷ U ₁ ⁸ C ₅ U ⁴ G _: ^. G _o U ^N _t G ^e A _k ^c C _o C ^D U ^y C _e A ⁿ _r C ^ot _t A C A U G U U A C C A C A A A C C C C C C A U G C C C A C G U C C U U C C C C A AUUCCC UCUGGCCC AUUCAAU UGUC₂ AUUCAAU UG GGCGCA UCCCGUUGUC^A- A UCCCGU U AGGGUUU U CCAGGCUGUGCC CG AGGCUGUGUG C C GC C CA AUA C CA ACU CG UC A CUA C CG U UCC GGGU G G GUUA C G G UA CC GCUAGA G G UGC C G G UGC U CC ACGGCG CU G GAC U C A AUU C CC U G GA A AUU C AGGGCU G AGC G G A AGC G C CUG GGC CC C U C G C C C₀ ⁰ mUA CAUCACmUA UGCUACCU 1 - mUA UGCUA C ^GCGGGACCCCCC^GCGGCCGCGUA ^GCGGCCG GU G^A _p AG _p GGA C₀ A- ^p _pC ⁰ _p GGA C C UG U CUC U A CGA U A CG CGA C GGC CA UAUC^pCGAGU GC C₁ ^pCGAGU GC G UC CG_p C G G A UAC G G _p C GA U C G UA ACC G GGGC A C ^A C G^G ₇ G GA CGUG ^G ₇ C - ^G ₇ GGGGG CAG C G G AU GGUAUUCGCGAC GGUAUUCGC C G m U C G G C U G A A C C m U C G A G A C U G G C G m U C G A G A C U G 2⁰ _{3 2} ⁰ _{4 2} ⁰ ₂ 3^t m ^: c ^{G l} _{) i} Q⁷ ₁ ⁴ m ^:l _{i e} ⁵ m ^:l _{) i} Q⁷ ₁ u_{r p} ^{a t} ES ^{1 t} _: ^t _c ^G _p ^{a t} - G ^{t d n} _i D⁾ _c ^G _p ^{a t} ES ¹ _{: s} ^{p n} _{: o 5} ^p _p A ⁽ a ^G _{7 y t} l_o ⁿ O ^u _{r 0} ^{N t} _s ^{p 0 n} _{: p} A- A _e ^{t - d} o ₅ ^p _a ^G _{7 y} ^l _{0 o} ⁰ ₁ U- C⁰ _{r 2} ^e _{y v} ^x _i ^I ₃ ^u _r ^{t p} o^{e m} _y Q ¹ E_{: s} Oⁿ _{: p} A ⁽ o ₅ ^p _a ^G _{7 y t} l_o ⁿ O 0 ^N C G C m P ₁ ^D _I C G C m P A U Aⁿ _{i d} ^h _t ^S ₍ N C G C m P⁰ ₁ ^D _I

A CU AGG G GGCCC GGAU AGGUCGGGCGCC AGGUC AG C CG UCGGGCGCG CGUCGAUU CACCG CGUGG AA GCU CCGAUUACA C A CCGACGGGCCG CCGCA AG CGGCACGCGCA G G CGGCCGUUCCCG G CGAGC CU UAAGCGUG UCCAU UAAUAACCGCUU UACAA CC CGGAAACCGCC CC CGGCCGCCAUAG CGGCC CU UAUCUGCCAUCU UAUAAUAGGCC CA UAUAA ⁰ GG G ₂ ^. ₀ GA ⁸ ₉ GA UAXT UU ^M CA _/ CA ₁ C CGO GU U ^W ₇ UU ⁷ U CC ₁ ⁰ UU -⁷ ₁ UG G ⁸ AU ₅ ⁴ CG _: C ^. U _o UU ^N C AA _t ^e CA _k ^c AU _o CU ^D UA ^y GA _e UA ⁿ _r UU ^ot _t AA A A C CA AG CA AA AC AG CU CC GC AU UU CC CC GC GC UU GC GC CU UC CC CC GC AG CA CC UC CC AC CC AC CU UA GC C UU A UC AUUCAAUUU C A UCCCGU C^A- A UCC UCCCGU GUUU AUUCUGUGUGU CC CG AUUCU AA CC₀ ⁰ AG CUGUGUGUC- AGGGUUAUCCAUA AGGGU GCG CGGUUAUCC CCAA₀ ⁰ GCGGG C C A C GC GG A C CC C UG G CCU CG C ₁ AC^AGCUGGUG GAC ₁ G A U C C G A A AUU C A^A CU GAU G A CU G CCC C ACUU C U- AGC G mUA UGCG AC UACU- AG UG C m A C CU UAC- AGG C C C CC GC GC AGG^G _pCGGCCGC U UA G CGGG G A CG CGAC₀ ⁰ mUA C GG G CG G ^G _p AG C₁ ^G _p G AUG^pUG GAAGCGAUG ^pUGAGUGACUAC^{A p}UGAG AUC_pCCAGUG CUAUC _pCCGGGCCAGCG- CCGA CAG GGGGGCA CAGCAG GGUAUUCGCGAC _pGGUA GCG^G ₇ GGUAUUCGCGCG ^G ₇ GGGAGACUGGCG ^G ₇ GGGA G C G m U C G A G A C U G G C G m U U G G C C C G G G C G m U C G G 5⁰ _{6 2} ⁰ _{7 2} ⁰ ₂ 6^t m ^: c ^{G l} _i - _e ^7t m ^:l _{i e} ^{8t u} _{r p} ^{a t} _s ^{p t} G ^{d n} _i D ^{I )} _{3 c} ^{G u} _p ^{a p t} - G ^{d n} _i D ^{I )} _{3 c} ^{u n} _{: o} ^p _p A- ^G _y ^l ₀ A 0 U- _e ^{t 0} _r - ^e _y ^{d x} _i mQ ¹ _{r :} ^t _s ⁿ _: ^p _p A- ^G _{y 0} A _e ^{t - 0} U-⁰ _r ^e _y ^{d x} _i mQ ¹ _{r :} ^t _s ⁿ C ₅ G _a C₇ m _o P₁ C A U₂ A_v ⁿ _{o i} ^e _{d y} ^h E t ^S ₍ O N_o C ₅ G _a C₇ ^l m _o P₁ C A U₂ A_v ⁿ _{o i} ^e _{d y} ^h E t ^S ₍ O N_o C ₅ G

C CC CCG C UCUUA ACACCU ^t _′ UU C- _c ^{u e} _c ⁺ m ⁵ _{e )} ^o _{r :} ^d Q ^c _{n ′} ³ Q n E^, ₆ ^e _u D^d E¹ ₄ UUCC UGGC⁰ _r ⁿ R UC₂ ^t _{s e} T ⁺ R ^f D ^{I 0} ₅ ^s _t ^e S s _{′ f} ^{o 5} _: ^q O_e ^I _n S S Q ^a _{, f} ^{o 1} _: GU UGUG CCUC^A- AUG ⁿ u o ^q _e ^U _’ F T RU ^{2 ’} ₀ Q_{: i} O^{s 3} n ^o _t RT ^NF E⁹ R ^S _: O ORT ^{N 0} AU ₂ CC ^{5 5} E ^{o ′ D f D .} GC ₀ ⁸ UU ₉ GC GCXT AC GG ^M _/ CA ₁ UC O AC C^W CC ₇ G ⁷ ₁ AG ⁰ CU -⁷ GG ₁ AU ⁸ ₅ GC C ⁴ U _: ^. GA _o AC GA AA ^N U UGAG AAAGAG C CG C AG UGCAGGU _t ^e AA AAAA AAC C U_k G^c CU CU CGUAGCGGCUC_o U CG S AC GC GUGC CUAG C UCGGA A ^D GG GGAGCA T GG C CCUG UG UCAGG U ^y G UUAUA N C CGGA U GGCC _e UG C Aⁿ AC _r CAC ^ot C _t CGG G A AU GU ACC G GAG U GC ACG C CUG CAG GCA GU AG GCG G UCG U CA ACG C UGU CGG AC AG G CAU UUG UCG CUU CGC GAG CAU GGG GAG GGG UCU GAU GAU GCU AAC CGC GGC CGC_i UUGGCCCm C ⁿ _i S _P Y P d d LLQ Y G^S EYDLS DQY UCAUAUA^y _h ^{n i} ACAG GACU^t _{- o c} ^e LVG_S KT A^E _P P F S R^S DRS GM T ^GS _I MCWV UAC GC CUGG G GGC^y _x ^p A_c TRQ_{F P} GTF QYYE AUC C^o _s ^e _o ⁿ _e VAV^GAGRLYD^{F I} _S AC A CCCC C_e ^d _r ⁿ _i u P AL_S Q RGGYV_P S U C CCUCCA^{d r} _o m^q L AHGAV^S _I KLAP V GGCUAUC_e ^t C A_e S ₆ MLGA L G S LTTET UCACCCG_r C W S S N D G V GCGUGAU^e _v C U G A A C Cⁿ _i 1^t _c A ^u _r N_e ^t R^m _s ⁿ m ^: m_a N _o C G ^l _{i p} ^a : ^{p t} - _e G ⁿ A- A ^d _e - _i ^d _i D ^{I )} _{3 :} p _{p a} ^G _y ^l ₀ ⁰ U- ^{t 0} _r ^e _y ^x _o ^mQ ¹ E_: Q E ^DO C ₇ m _o P₁ C A U₂ A_v ⁿ _i ^e _{d y} ^h _t ^S ₍ O N S _I N

^t _{′ c} ^{u e +} m ⁵ r _c ^o _: t_s ⁿ R ^{d +} _{) r} ^f _n ^{e n} _eu T R F T D ^{I 1} ₅ ^{s 2} _{t ′ :} ^s _i ^{s 3} o ^{q U} _’ RU ₁ Q _n ^o _t ⁰ C_e S ^{5 ’ 5} EO^{o ′} ₂ ^. ₀ ⁸ ₉ c X Rⁿ T T _{e /} ^Uu ^{M ′ q} 3 _{e 1} S O ^W ₇ c ⁷ Rⁿ ₁ T _e ⁰-^{7 U}u^q ₁ ^{′ 8} _{5 e} S ₅ ⁴ _: ^. _o ^N _t ^e _k ^c _o ^{D y} _e ⁿ _r ^ot _t A )_edⁱ _t ^o _e ^l _cu N ^{( e} _c ⁿ _eu^q _e ^S F R O g VP ^{I n} _i H^I GG_I LE P GF A KG LVLA TH P LS Y L S dⁿ dⁱ _I F VA c T R K QG^S GLP VV YL LV TVVT L^QG _{P F o} ^p _s A^e _c ^{N e} _{r o} ^{n r n} _{i e S} ^S K_P VLV^Q _I GE AT_P QTF CVL u EL ^LK^D _S Y R T V V ALGS H^W _S L E P YRKQ LAGA o m^q C A_e N S DK_FP CVEN L G K A W^Y _S RQ ₀ P ² AHG 2 ML A LG S C S 2^t _c A ^u N_{e r} ^t _s R^m m_a ⁿ N _o C Q _: E ^DO S _I N

^t _{e c} ^{u e} r _c ⁺ Q ^{c t} ₎ ES ^, _{n 6} ^e _u ^d D_{n s} ^{n n} _e R ^{I a} _{, f} ^o u T ⁺ R _f ^{o 5} _: ^q O_e ^S Q⁰ ₃ RD ^{I 1} _{4 o} ^{q U} _’ F T RU R F E² T ^NR ^S _: T ¹ O ^UQ_: ⁰ _e ^{’ f ′} EO ₂ ^. C S ^{5 D} ₀ ⁸ ₉ c X Rⁿ T T _e ^M _/ ^Uu^q ₁ ^′ _{3 e} S O ^W ₇ c ⁷ Rⁿ ₁ ⁰ T _e - u ^{7 U} ₁ ^{′ q} _e ⁸ ₅ S ₅ ⁴ _: ^. _o ^N _t ^e _k ^c _o ^{D y} _e ⁿ _r ^ot _t A )_edⁱ _t ^o _e ^l _cu N ^{( e} _c ⁿ _eu^q _e ^S F R O W F ^T P g EAS A NRRLYKS L _I ^T P T^P VP VF^I A_S K n_i P Y EYDLS DG_PP H d d KT ^I GG_I P F ALE GH S R^S NRS Q GY_I G TF VAK RT YK n ^{i G} _{S I} MC M LVV L o _c ^e _P GT W GP TVVT p_s A_c AGF QY V e RLYYE^N _S ^S _P VLV^Q _I GE Y r _o ^{n r n} _{i e} Q D^I u R^GGYV^F _S KCVL^LK^D L_S T o m^q V_S ^I KLTAT_P S EL _S P H^WYRKE Q C A_e S W_SS LS N VN S V D KDET E G VDK_FP CVE L G K A W^Y _S N RQ P A N_e R^m m_a N

^t _{′ c} ^{e +} m ⁵ _{e :} Q ^c _n ^{e d u} _{r c} t_s ⁿ ₎ ^o _r ^{d n} _e R _n E^, _{6 u} D_n ^a _f u T ⁺ R ^f D^{2 s} _t ^e S ′ _f ^{o 5} _: ^q _e ^I _, ^o Q¹ RD^{1 0} _o ^{q U} _’ F T ^I ₅ RU ₂ Q² _: ^s _i O^{s 3} O ^S ₃ ^I _{4 n} ^o _t RT ^NF E² R ^S _: T UQ¹ _{: 2} ^. C_e S ^{5 ’ 5} E ^{o ′ D f} O^′ EO₀ ⁸ ₉ c X Rⁿ T T _eu ^M _/ ^{U′ q} 3 _{e 1} S O ^W ₇ c ⁷ Rⁿ ₁ ⁰ T _e -^{7 U}u ₁ ^{′ q 8} _{5 e} S ₅ ⁴ _: ^. _o ^N _t ^e _k ^c _o ^{D y} _e ⁿ _r ^ot _t A )_edⁱ _t ^o _e ^l _cu N ^{( e} _c ⁿ _eu^q _e ^S F R O g n L i P L^L d d L _S YGT^S R^S S NVT VDK_FP C AVYN R_PP LQRN^S K_{S I} R LG TMCL^YK^KL^WS T ^T _S K n_o ⁱ _c LV^{E G} _FT^{G p} _P G D_F QYT_P V_SP V_F ^I _{I I} ALE H s A^{e e} _{r o c} A n T_{P P} QF A_S RLYG Q^P _P H^I G VR ^P G GF AGK AVGS Q^N _I GYV KLAGY_IT_F VA VKT YL r ⁿ _{i e}u P o LAVAR V^NVTTWMGLP VTR T VVE m^q ₁ AHG _S GAWL_S N DKDEYV^{E N} _S S VV^QGY C A_e S ² ₂ ML L GC S Q W A A AD F _I P L S K C VL L_I KD S T E 3^t _c A_e ^u _r N ^{t m} _s R_a ⁿ m N _o C Q _: E O S ^D _I N

^t _{′ c} ^{u e} r _c ⁺ m ⁵ _e t_s ⁿ ₎ ^o _{r :} ^d Q ^c E^, _n ^e _{′ u} ³ Q D^d E^{1 n} _e R ⁺ R u T D^{0 fs} _n S _{6 t} ^e _f ⁵ _: ^q _e ^I _n ^a S_{f 4} ¹ _: ⁰ _o ^q _e ^U _’ F T ^I ₅ ² ₂ ⁵ RU^’ ₀ ⁵ Q_: ^s _{i ′} ^{o s 3} O ^S Q_, ^o O R F E⁹ _: EO_n ^{o o} _t ^{N ′} T^DR ^S R ^{N f} OT^{D .} C S ₀ ⁸ ₉ c X Rⁿ T T _{e /} ^Uu ^M ₁ ^{′ q} 3 _e S O ^W ₇ c ⁷ Rⁿ ₁ T _e ⁰-^{7 U}u ₁ ^{′ q} _e ⁸ ₅ S ₅ ⁴ _: ^. _o ^N _t ^e _k ^c _o ^{D y} _e ⁿ _r ^ot _t A )_edⁱ _t ^o _e ^l _cu N ^{( e} _c ⁿ _eu^q _e ^S F R O gⁿ i P LLS Y_P YNRLDQP H^I P GF KGH dⁿ d LLQ VG^S EYD TRS RGY_ITF VA TK VRYL o ⁱ _c ^e L^EG_S K P F ^GS ^S _I DS CWMGLP VTVVT p A_c AT_P e RQ^T _{F P} S GTMYYVE^NS _P VLV^Q _I GE s _{r o} ^{n r n} _{i e} VAV u P ^GAGF Q RLYD^I _{S S} KCVL^LK^D _S YT LAL G_S Q RGGYV^F _P S EL^W _S L RKE o m^q AH A G V^S _I KLTATPEVTNH K_F Y P CVEQ C A_e S ₆ ML A L G C WS S L S N D G VD L G K A W^Y _S N RQ P 4^t _c A_e ^u _r N ^{t m} _s R_a ⁿ m N _o C Q _: E O S ^D _I N

^t _{′ c} ^{u e} r _c ⁺ m ⁵ _e o ^t _s ⁿ R ⁺ _{) r :} ^d Q ^c E^, _n ^e _{′ u} ³ Q d E 3 ^fs _n ^e S_{f 6} ⁵ _: ^q D e ^I _n S_{f 0} ¹ _: n _eu T R F T D ^I _{5 o} ^{q U} _’ RU ₃ Q² _{t :} ^s _{i ′} ^{3 o} O ^S Q ^a _, ^o O O^s _n ^o _t RT ^NF E⁹ R ^S _: R ^{N 0} _{e 2} ^{5 ’ 5} E ^{o ′ D f} OT^{D .} C S ₀ ⁸ ₉ c X Rⁿ T T _{e /} ^Uu ^{M ′ q} _{e 1 3} S O ^W ₇ c ⁷ Rⁿ _{1 e} ⁰ T -^{7 U}u^q ₁ ^′ _{5 e} ⁸ S ₅ ⁴ _: ^. _o ^N _t ^e _k ^c _o ^{D y} _e ⁿ _r ^ot _t A )_edⁱ _t ^o _e ^l _cu N ^{( e} _c ⁿ _eu^q _e ^S F R O g LVR WAS ART^P V n_i P LLA^EYNRP G_P H dⁿ d LLQS Y_P G^S EYDLDQP ^I RS RGY_IT o ⁱ _c ^e LV^EG_S KT P F ^GSS ^S _I DS CWMG p_s A_c A e_{r o} ⁿ T_P RQ^T _{F P} TM YV^N AGF QY E^I _S r ⁿ _{i e} V u P AV LAL^G e G_S QG ARGRLYD S GYV^F _SS KE L _{P o} m^q AH 6 GAV_I KTATPEVTN C A S ML L G C WS S L S N D G VD L 5 A ^t N_{e c} ^u _r ^t R^m _s ⁿ m_a N _o C Q _: E O S ^D _I N

^t _{′ c} ^{u e +} m ⁵ r _c ^o _: t_s ⁿ R _{) r} ^{f d} _n ^{e n} _eu T ⁺ R F T D ^{I 3} ₅ ^{s 2} _t ^s _{i ′} ^{3 0} _o ^q _e ^U _{’ 2} ⁵ RU^’ ₃ ⁵ Q_: ^s EO_n ^{o o} _t ^{′ .} C S ₀ ⁸ ₉ c X Rⁿ T T _eu ^M _/ ^U ₁ ^{′ q} 3 _e S O ^W ₇ c ⁷ Rⁿ ₁ ⁰ T _e -^{7 U}u^q ₁ ^′ _e ⁸ ₅ S ₅ ⁴ _: ^. _o ^N _t ^e _k ^c _o ^{D y} _e ⁿ _r ^ot _t A )_edⁱ _t ^o _e ^l _cu N ^{( e} _c ⁿ _eu^q _e ^S F R O g P n_i GG^I _I P ALE LVRA d F GF GH P LL AKTK LQS Y n dⁱ V c L ^S VVRYL L TV T LVG G_{S o} ^e P V VE A^EP F p_s A e_{r o c} ^{S n} _P LV^Q _I G _P ^T CVL^LK^D _S Y TRQ T ^VAV_F G ^{r n} _{i e}u L H^W _S L RKE _PLAL_{S o} m^q C A_e K_F Y P CVEQ S N G K A W^Y _S RQ AHGA P ₆ MLGA L G C 6 A ^t _c N_e ^u _r ^t R^m m_{a s} ⁿ N _o C Q _: E ^DO S _I N

^t _{e c} ^{e +} Q ^c _n ^e _′ ³ Q u_{r c} t_s ⁿ ₎ E n _e R S ^, _{6 u} D^d E₀ u T ⁺ R _f F T ^{o 5} _: ^q O_e ^I _n S S Q ^a _{, f} ^{o 1} _: F E⁹ _: O o ^{q U} _’ RU RT ^{N S} R ^{N 0} ₂ ^. C_e S ^{5 ’ D}R^f OT^D ₀ ⁸ ₉ c X Rⁿ T T _eu ^M _/ ^{U′ q} _{e 1 3} S O ^W ₇ c ⁷ Rⁿ ₁ ⁰ T _e -^{7 U}u^q ₁ ^{′ 8} _{5 e} S ₅ ⁴ _: ^. _o ^N _t ^e _k ^c _o ^{D y} _e ⁿ _r ^ot _t A )_edⁱ _t ^o _e ^l _cu N ^{( e} _c ⁿ _eu^q _e ^S F R O g W n_i ^EAS ART P YNRP G^P _P VP VF G^I _I ALKE DLDQP H^I G I P GF A KGTH dⁿ d o ⁱ EY c KTRS DR Y F VA S G TL VRYKL p ^{e G}SS ^S _I MG MCWV P V s A_{c P} T Y ^NS VTVVTE e AGF QY E^I _{S P} LVL^Q _I G DY r _o r ^{n n} i _eu QGRLYD o RG ^F _S KC m^q V^S _I GYV LV^LK S L_S TE KLTA_P S E TPEVNH^W _F YRK VEQ C A_e S WS S L T S N D G VDKP C L G K A W^Y _S N RQ P A N_e R^m m_a N

^t _{′ c} ^{e +} m ⁵ _{e :} Q ^c _n ^{e d u} _{r c} t_s ⁿ ₎ ^o _r ^{d n} _e R _n E^, _{6 u} D_n ^a _f u T ⁺ R ^f D^{1 s} _t ^e S ′ _f ^{o 5} _: ^q _e ^I _, ^o Q⁰ RD^{1 0} _o ^{q U} _’ F T ^I ₅ RU ₁ Q² _: ^s _i O^{s 3} O ^S ₃ ^I _{4 n} ^o _t RT ^NF E² R ^S _: T UQ¹ _{: 2} ^. C_e S ^{5 ’ 5} E ^{o ′ D f} O^′ EO₀ ⁸ ₉ c X Rⁿ T T _eu ^M _/ ^{U′ q} 3 _{e 1} S O ^W ₇ c ⁷ Rⁿ ₁ ⁰ T _e -^{7 U}u ₁ ^{′ q 8} _{5 e} S ₅ ⁴ _: ^. _o ^N _t ^e _k ^c _o ^{D y} _e ⁿ _r ^ot _t A )_edⁱ _t ^o _e ^l _cu N ^{( e} _c ⁿ _eu^q _e ^S F R O g n L i P LS YP S EYDLS DG_PP H^I GG P GF AGH d d LLQG TR RQ V ^S K^{S S} NS GY_ITF VAK RT YK n ⁱ L ^G _{P F} ^G _{S I} C M LVV L o _c ^{e Q} T_P TM W GP TVVT p A_c AT_P Q e R F AG GF QY V L YE^NS _P VLV^Q _I GE s _{r o} ^{n V} V ALGS Q^GR Y GYVD^I _{S S} KCVL^LK^D _S YT r ⁿ _{i e}u _{P o} LAGAR m^q ₀ AHGAV_S ^I _S KLA^F _P S EL^W _S L RKE S LT S NTPEVTNH K_F Y P CVEQ C A_e S ² ₂ ML LG S C S W S V D KD E G VD L G K A W^Y _S N RQ P 7 A ^t _c N_e ^u R^m _r ^t a _s ⁿ m N _o C Q _: E O S ^D _I N

^t _{′ c} ^{u e} r _c ⁺ m ⁵ _e t_s ⁿ ₎ ^o _{r :} Q ^c _n ^{e d n} _e R ^{f d} _n E^, _{6 u} D_n ^a _f u T ⁺ R D^{2 q U}F T ₅ ^s _t ^e S ′ _{f 2} ^{I 2} _: ^s _i ^{o 5} _: ^q _e ^I _, ^o Q¹ RD^{1 s 3} O ^S ₃ o R ^NF E² _: T ^I ₄ ¹ _: ⁰ _{o e ’} RU^{’ 5} QEO_{n t} ^′ T R ^Sf O ^UQEO ₂ C S ^{5 o D ′ .} ₀ ⁸ ₉ c X Rⁿ T T _eu ^M _/ ^{U′ q} _{e 1 3} S O ^W ₇ c ⁷ Rⁿ ₁ ⁰ T _e -^{7 U}u^q ₁ ^′ _e ⁸ ₅ S ₅ ⁴ _: ^. _o ^N _t ^e _k ^c _o ^{D y} _e ⁿ _r ^ot _t A )_edⁱ _t ^o _e ^l _cu N ^{( e} _c ⁿ _eu^q _e ^S F R O g D N ^{Q n} L i P VR L^LYL GT^S RS T _F CREN_P NV DKP VYRP d d LLQ_S RN^S K_S ^S _I RVLG A S MCL^{Y K}L^{WT T}K n ⁱ _c LV^{E G} _FT^GG^T _F QYT_P K V_SP V_F ^I _{I S I} ALE o ^e A_{P P P} ^DRLYG^P GG H p_s A e_{r o c} ⁿ T QF A_S Q_P H^I F AGK VR AVGS Q^N _I GYV KL GY_IT^P _F G VAKT YL r ⁿ _{i e}u P AVAR o L V^NVTATWMGL VR T P VTVVE m^q ₁ AHG _S GAWL_S N DKDEYV^{E N}S VV^QGY C A_e S ² ₂ ML L GC S Q W A A AD F _I S _S P L K C VL L_I KD S T E 8 A ^t N_{e c} ^u _r ^t R^m _{a s} ⁿ m N _o C Q _: E O S ^D _I N

^t _c ^{u e} r _c ^{+ t} _s ^{n n} _e R ⁺ ₎ R u T q ^UF T o _{e ’} RU ⁰ ₂ ^. C S ^{5 ’} ₀ ⁸ ₉ c X Rⁿ T T _eu ^M _/ ^{U q} _{e 1} ^′ ₃ S O ^W ₇ c ⁷ Rⁿ ₁ ⁰ T _e -^{7 U}u^q ₁ ^′ _e ⁸ ₅ S ₅ ⁴ _: ^. _o ^N _t ^e _k ^c _o ^{D y} _e ⁿ _r ^ot _t A ^t _s ^{e n} _{r o} ^{a n} _a ^r _e ^C _f 6 _e ^f _f ^{i f o} NE C ^c _{n d o s} ⁿ _o U )_e ^. dⁱ ₃ ^d _n ^{a e} _{u 7} ⁱ _t Q t C _d ⁿ _i ⁱ _d E o P _, ^{5 q} _e ^{n e} e _{a t} ^{o d} _a ^S T l_c ^G _, ^s _r u ^{n 4} a ^, R ₂ ^p 1 ^e _e ^h _t C U N ^{( m e} _{u s} D t ^I _s ^{t n} _c ^u _h T ^r _{9 e} R ⁹ _{1 c} ^h _{c a r} ^t _. ^{) h} _t T i S d ^u _r ^t _{f s ) s} ^{o n} _o ^l _{i e} ⁽ N n_{e n} u ^{i q} _b ⁿ _o ^{n a} o ^C _{t e} R O T ^C _{“ e y} S ^l _l ^{C i a} F _c ^f _t ^{i f} d _o ⁿ _i ^{d U} _d i _{o s} ^d _{s a} A _i ^{’ e} m _{3 l} ^t _i ^t R _f ⁱ O _c ^{n e} _{i e} ^h N R ^h _{t r} ⁱ _{e n} ^e p ^e _t s ^o t ^{y t} _r ^{r m} _x ^{h o} _tf ^e _{v a} ^p _e e ^h _t ^{e i} _h ^t _e ^{d o n o} _{b g} ^{h n} _{t h e i s} ^{T (} _{( e} ^d _e ^t _o ⁱ _t ^{a e} _l dⁿ d R ^. ₃ R T m^a _r ^{e r} _o ^{p b} _{a o} ⁱ _c p ^e A C CP U^’ _{s v e} ⁿ _i ^{a T} s A ^{e e} _{r o c} r ^{n n} _{e i e} ^{r G} _3r ^h _{t n} ^{a n} i _h u _a ⁿ _a ⁱ _{e e} ^r o m^q _a ^{r r} _e T n C A_{e 8} S _h ^{m h} _{t o} g _{u f 7} ^/ _d ^f _f ^{i I} _{. u} ^{h o} _d ^{n o} _{a d 8} ⁾ ₎ ^l _{i r} ^{s n n h} _{d o t} ^{n i} _{a e 2} ^c _d ^{a n} _{t e 1 i} ^b _t ^r _{o s} ^t _{n a c} ^e _{u 3} ⁿ _i ^d A N_{e s} ^{t t} c _a ^{p h a u} _r ^q _{e s} ^t _i m R^m _a ^u _{r t} t_{s y} ^{n t} i ^{t r} _s ^s _c n_o R ^u _r ^t _{h s} ^t _y m N ⁿ _{e o} ⁱ _{o e} ^f D f^{i C I n} _o ^x _o C m _d ^f _o ⁿ _a C ^e _d

⁰ ₂ ^. ₀ ⁸ ₉ X ^l _i T ^a t ^M _/ ^A ₁ ^y O _l ^{o W} _{7 p} ⁷ _{a 1} ⁰ _e - ^{d 7} _{1 u} ^{l 8} _{c 5} ^{4 n} _{i :} ^. _o ⁿ _a ^N _t ^{c e} _k A ^c N _o ^D R ^y m _e ⁿ _{e r} ^{h ot} _{t t} ^t A _a ^h _t d_o ^o _t ^s _r ^e _d ⁿ _{u e} ^{b o} _{t o} ^s _l ^{a s} ₀ i ^{0 t} _{2 i} ^; ₆ ⁵ _: O N D ^I QE ^Sf _{o d} ^a _e ^t _s ⁿ i ^{. 7} _{) :} ⁷ ₁ O ^{1 N r} _o D ^I ₃ ¹ Q _: E O S e ^{N s} _i D r ^I p Q m E o_c S, n _. a ^g _{. c} ^e ₍ Attorney Docket No.: 45817-0177WO1 / MTX980.20 EXAMPLES Example 1 5 In Vitro CAR Expression Human macrophages were transfected in vitro with lipid nanoparticles (LNPs) containing mRNA encoding various CAR constructs (Construct 1, 2, or 3) or a control mRNA sequence. Schematic diagrams of Constructs 1, 2, and 3 are depicted in FIG.1. The binding domains comprised anti-GPC3 variable domains of heavy-chain antibodies 10 (VHHs). Construct 1 comprises the VHH set forth in SEQ ID NO:2; Construct 2 comprises the VHH set forth in SEQ ID NO:150; and Construct 3 comprises the VHH set forth in SEQ ID NO:151. Human Macrophages transduced with a CAR-mRNA containing LNP (mRNA/LNP) were stained for CAR expression using recombinant human Glypican 3 15 (GPC3)-His Tag labeled with AF647 fluorophore. Viability was detected using Aqua Live/Dead stain. LNP2 was used for testing in this study (see, FIG.2); LNP2 comprises Compounds I, II, IV, and cholesterol. Cell viability (upper left panel) was not altered by addition of mRNA/LNP, with all cell populations being equally viable relative to an untreated (UTD) macrophage control. Only macrophages transfected with mRNA/LNPs 20 containing CAR-mRNA were capable of binding soluble GPC3, leading to increased CAR detection via flow cytometry when compared to untransfected (UTD) and Control Construct mRNA/LNP transfected macrophages (rGPC3 MFI and % rGPC3). The upper right panel shows the fluorescence intensity and the lower panel shows the percent positive cells. See, FIG.2. 25 Human macrophages were transfected in vitro with LNP comprising control mRNA or mRNA encoding a CAR construct (Construct 1, 2, or 3). Macrophages were plated at 20,000 cells per well, followed by administration of mRNA/LNP at a final concentration of 9 nM. Macrophages were incubated overnight. Following overnight incubation, media was exchanged from macrophage wells to remove remaining 30 mRNA/LNP, and tumor cells expressing target antigen GPC3 were added at a density of 201 Attorney Docket No.: 45817-0177WO1 / MTX980.20 10,000 cells/well. The tumor cell lines include HEPG2, HUH7, and HEP3B. All tumor lines were engineered to express nuclear-localized GFP and imaging of culture over time was done using the IncuCyte Live-Cell Analysis System. The change in fluorescence over time was measured to determine the amount of 5 tumor cell killing that occurred within the co-culture, which was detected via reduction in GFP intensity relative to time 0. Calculation of tumor burden was done using the following equation: (Change in Tumor cell Burden = Integrated Intensity of Experimental well (norm.to t=0)/Integrated Intensity of avg. UTD (norm.to t=0)). Constructs 1, 2, and 3 all demonstrated killing of GPC3 expressing tumor cell lines at a 2:1 E:T ratio relative 10 to control construct macrophages. FIG.3. Example 2 In Vitro Cytokine Release by Transfected Human Macrophages Macrophages were tested for their ability to secrete cytokines in response to 15 immobilized antigen. First, the target antigen GPC3 or irrelevant antigen HER2 were brought to the indicated concentrations (20, 2.0, 0.2, ug/ml) in PBS. Next, 100 µL of antigen solution was added to wells in a 96-well plate and incubated at 4°C overnight. After incubation, wells were washed three times with 150 µL PBS. Untransfected macrophages were resuspended at a density of 1X 10⁶ cells/mL, and 50 µL were added to 20 each well (50,000 macrophages/well). The macrophages were then incubated for 4-hours at 37C and 5% CO2. mRNA/LNPs were diluted and 100µL were added to the appropriate wells for a final concentration of 9 nM. Plates were then incubated for 24 hours and centrifuged for 5 minutes. Subsequently, ~125 µL of supernatant was removed and stored at -80°C. 25 Macrophages transfected with CAR-mRNA containing LNPs (Construct 1, 2 and 3) showed titratable secretion of proinflammatory cytokines (TNF⍺, IL-6, IL-1β, and IFN^^) in response to immobilized GPC3, but not immobilized HER2. FIG.4. Macrophages transfected with Control Construct mRNA/LNP only showed slight increase in IL-6 secretion but not other proinflammatory cytokines. FIG.4. 202 Attorney Docket No.: 45817-0177WO1 / MTX980.20 Example 3 In Vivo Efficacy in Tumor Bearing Mouse Model Humanized (hCD34) NSG-S mice were I.V. injected with 1 X 10⁶ Panc1 tumor 5 cells engineered to express GPC3 and luciferase. Four days post tumor implantation mice were injected I.V. with either vehicle, Control Construct mRNA/LNP, Construct 1 mRNA/LNP, Construct 2 mRNA/LNP, or Construct 3 mRNA/LNP. All mRNA were formulated in LNP2 in this study. mRNA/LNPs were dosed either 2 times per week (2x/wk) or 1 time per week (1x/wk) and dosing continued for 8 weeks after the first 10 injection. All treatment groups were dosed at 2 mg/kg. Mice injected with LNP comprising Construct 1 and 4 both showed reduction in tumor burden as determined by whole body bioluminescence imaging, while those injected with LNP formulated with the control construct showed tumor growth similar to vehicle alone. See, FIG.5. Ex Vivo bioluminescence imaging of the livers showed significant decreases in 15 liver tumor burden in mice treated with LNP comprising Constructs 1 and 4 relative to LNP comprising Control Construct (FIG.6, left panels). Histology of livers stained for GPC3 showed a reduction in GPC3+ lesions in the livers of mice treated with LNP comprising Constructs 1 and 4 relative to mice treated with LNP comprising Control Construct (FIG.6, right panels). 20 Example 4 In Vivo PANC1-NSGS Anti-Tumor Efficacy of Various Constructs Humanized (hCD34) NSG-S mice were I.V. injected with 1 X 10⁶ Panc1 tumor cells engineered to express GPC3 and luciferase. Four days post tumor implantation mice 25 were I.V. injected with either vehicle, Control Construct mRNA/LNP, Construct 1 mRNA/LNP, or Construct 4 mRNA/LNP. All mRNA were formulated in LNP2 in this study. Treatment groups were dosed at 2 mg/kg either 2 times per week (2x/wk) or 1 time per week (1x/wk) and dosing continued for 8 weeks after first injection. 203 Attorney Docket No.: 45817-0177WO1 / MTX980.20 Mice injected with Construct 4 mRNA/LNP showed reduction in tumor burden as determined by whole body bioluminescence imaging, while those injected with Control Construct mRNA/LNP showed tumor growth similar to vehicle alone (FIG.7, left panel). Ex Vivo bioluminescence imaging of the liver showed significant decreases in liver tumor 5 burden to day 39 in mice treated with Construct 4 relative to Control Construct (FIG.7, right panel). Histology of the liver stained for GPC3 showed a reduction in GPC3+ lesions in the liver of mice treated with Construct 4 relative to mice treated with Control Construct (FIG.8, right panel). Body weights of the mice did not differ significantly regardless of 10 treatment group . (FIG.8, left panel). Example 5 In Vivo Efficacy of GPC3 CAR Macrophages Using Various 15 mRNA/LNPs The efficacy of various constructs were tested using different LNPs for delivery. The constructs tested were Control Construct in LNP2; Construct 1 in LNP1; Construct 4 in LNP1; and Construct 4 in LNP9. Balb/C nude mice bearing HEPA1-6_hGPC3 tumor cells (clone P2-G7; 5x10⁶) were injected with 2mg/kg of LNP by tail vein injection two 20 times a week on days 7 and 21 post tumor tumor cell inoculation. Tumor growth (as measured by tumor volume BLI) and weight of the mice were measured. In addition, CAR expression was measured 15h after the first dose. After sacrifice, tumor and liver expression of CAR and GPC3 were measured by flow cytometry and tumor fragments and plasma were harvested. 25 CAR expression was observed in subcutaneous tumor cells of animals dosed in vivo with LNP comprising CAR mRNA constructs. As shown in FIG.9, right panel, the level of CAR expression in infiltrating immune cells was seen in all the groups tested. In particular, expression was seen in macrophages, dendritic cells, and B cells, although all 204 Attorney Docket No.: 45817-0177WO1 / MTX980.20 cells tested showed expression (left panel). There was little difference seen among the constructs tested, LNP9 seemed to provide slightly higher expression (FIG.9, left and right panel). When CAR expression in immune cells present in livers from animals was 5 examined, the Construct 4 in both LNP1 and LNP9 showed good levels of expression in the tumor. CAR expression was observed in livers of animals dosed in vivo with LNP comprising CAR mRNA constructs. As shown in FIG.10, right panel, the level of CAR expression in immune cells was seen in all the groups tested. In particular, expression 10 was seen in macrophages, monocytes, and dendritic cells, although all cells tested showed expression (left panel). There was little difference seen among the constructs tested, LNP9 seemed to provide significant higher expression, mostly in macrophages (FIG.10, left and right panel). 15   Example 6 In Vivo Efficacy of GPC3 CAR Macrophages using Various mRNA/LNPs The efficacy of various constructs was tested using different LNPs for delivery. 20 The constructs tested were Construct 1 and Construct 4 formulated in both LNP1 and LNP2 in a different tumor cell model. PANC1_hGPC3 cells were injected into mice tumor by tail vein injection at day 0. Mice were injected one or two times a week with the indicated mRNA construct in either LNP1 or LNP2. Tumor growth (as measured by flux) was measured and found to be lower in mice treated with each of the test constructs 25 in both LNP1 and LNP2. In addition, CAR expression was measured and was seen in all groups tested (FIG.11). Example 7 205 Attorney Docket No.: 45817-0177WO1 / MTX980.20 mRNA/LNP Transfection Generated Target-Specific and Highly Functional anti- GPC3 CAR-M in vitro Human macrophages were transfected with various amounts of lipid nanoparticles 5 (LNPs) formulated with mRNA encoding an ⍺GPC3 CAR construct or a control mRNA sequence. Macrophages transduced with a CAR-mRNA formulated with LNP were stained for CAR expression using either anti-VHH antibody labeled with iFluor647 (FIG. 12A) or recombinant human Glypican 3 (GPC3)-His Tag labeled with AF647 fluorophore (FIG.12B). Viability was detected using Aqua Live/Dead stain. 10 The data show that macrophages transfected with LNPs formulated with ⍺GPC3 CAR mRNA were labeled with anti-VHH antibody and capable of binding soluble rGPC3. Additionally, the level of anti-VHH and rGPC3 binding increased as more LNP was given to the macrophages, until saturation at 100% expression. Control construct macrophages showed no anti-VHH or rGPC3 binding. 15 Human macrophages were plated at 10,000 cells per well and transfected with various amounts of LNP formulated with control mRNA or mRNA encoding an ⍺GPC3 CAR construct (Figure 12C). Macrophages were incubated overnight. Following overnight incubation, media was exchanged from macrophage wells to remove remaining LNP, and HEPG2 tumor cells expressing target antigen GPC3 were added at a density of 20 10,000 cells/well. Tumor line was engineered to express nuclear-localized GFP and imaging of culture over time was done using the IncuCyte Live-Cell Analysis System. The change in fluorescence intensity over time was measured to determine the amount of tumor cell killing that occurred within the co-culture, which was detected via reduction in GFP intensity relative to time 0. Calculation of tumor burden was done using 25 the following equation: (Change in Tumor cell Burden = Integrated Intensity of Experimental well (norm.to t=0)/Integrated Intensity of target cells only (norm.to t=0)). Percent cytotoxicity was calculated by subtracting Change in Tumor Cell Burden at 72 hours from 1 and then multiplying by 100. 206 Attorney Docket No.: 45817-0177WO1 / MTX980.20 Macrophages given anti-GPC3 CAR mRNA LNP showed robust HEPG2 cell killing in a dose titratable manner. Untransduced (UTD) or control construct macrophages showed no killing of HEPG2 tumor cells. See, FIG.12C. Example 8 5 Anti-GPC3 CAR Expressing Human Macrophages are Highly Specific to GPC3 Antigen In this example, human macrophages were transfected with 9 nM of LNPs formulated with mRNA encoding an anti-GPC3 CAR construct or a control mRNA 10 sequence. Macrophages were incubated overnight. Following overnight incubation, macrophages were lifted, washed, and incubated with various members of the GPC receptor family for 1 hour at 4ºC. All GPC proteins contained a terminal His tag for detection. Macrophages were then washed and stained with an anti-His tag antibody to detect GPC binding. As a control, macrophages not incubated with GPC proteins were 15 stained with anti-His tag antibody. The results show that the macrophages treated with LNP formulated with mRNA encoding an anti-GPC3 CAR bound only to GPC3, and not to other members of the GPC receptor family. Control construct macrophages and UTD macrophages showed no binding to any GPC proteins. See, FIG.13. 20 Example 9 Kinetics of CAR Expression and anti-GPC3 CAR-M Tumor Cell Killing Human macrophages were transfected with 9 nM of LNP formulated with mRNA encoding an anti-GPC3 CAR construct or a control mRNA sequence. After overnight incubation, media was exchanged on all macrophages to remove LNPs. Macrophages 25 were stained with anti-VHH iFluor647 antibody on days 1, 7, and 14 to detect surface expression of the ⍺GPC3 CAR (FIG.14A). The data shows that CAR expression peaks at 207 Attorney Docket No.: 45817-0177WO1 / MTX980.20 day 1, followed by a decrease in expression over time. Control construct macrophages showed no CAR expression. Human macrophages were transfected with various amounts of LNP formulated with mRNA encoding an ⍺GPC3 CAR construct or a control mRNA sequence. After 5 overnight incubation, media was exchanged on all macrophages to remove LNPs. Macrophages were stained with anti-VHH iFluor647 antibody on day 7 to detect surface expression of the ⍺GPC3 CAR. (FIG.14B). The data show that higher concentrations of LNP lead to higher levels of CAR expression at day 7. Control construct macrophages showed no CAR expression. 10 Human macrophages were plated at 40,000 cells per well and transfected with 9 nM LNP formulated with control mRNA or mRNA encoding an anti-GPC3 CAR construct. Macrophages were incubated overnight. Following overnight incubation, media was exchanged from macrophage wells to remove remaining LNP. On days 1 or 7 post-LNP transfection, HEPG2 tumor cells expressing target antigen GPC3 were added at15 a density of 10,000 cells/well. The tumor line was engineered to express nuclear- localized GFP and imaging of culture over time was done using the IncuCyte Live-Cell Analysis System. The change in fluorescence over time was measured to determine the amount of tumor cell killing that occurred within the co-culture, which was detected via reduction in 20 GFP intensity relative to time 0. Calculation of tumor burden was done using the following equation: (Change in Tumor cell Burden = Integrated Intensity of Experimental well (norm.to t=0)/Integrated Intensity of target cells only (norm.to t=0)) Macrophages given anti-GPC3 CAR mRNA LNP showed robust HEPG2 cell killing at both days 1 and 7 (see, FIGs.14C and 14D, respectively), with a slight decrease 25 in killing function at the day 7 timepoint. Control construct macrophages showed no killing of HEPG2 tumor cells. 208 Attorney Docket No.: 45817-0177WO1 / MTX980.20 Example 10 rGPC3 does not Inhibit CAR-M Activity at Physiologically Relevant Concentrations Serum from normal donors and stage I, II, II, and IV hepatocellular carcinoma patients were tested for soluble GPC3 levels using a GPC3 ELISA kit (R&D Systems). 5 Soluble GPC3 was quantified following the manufacturer's instructions. The data show that the level of soluble GPC3 increases as the stage of disease increases. See, FIG.15A. Macrophages transfected with 9 nM of LNP formulated with mRNA encoding an anti- GPC3 CAR construct or a control mRNA sequence were incubated with various amounts of soluble GPC3 (sGPC3) and HEPG2 tumor cells in cell culture medium for 2 hours at 10 4ºC. HEPG2 cells were engineered to express nuclear-localized GFP. After 2 hours, cell mixtures were washed of sGPC3 and stained with CD11b-APC/Cy7 antibody and Live/Dead Yellow. The binding of macrophages to HEPG2 cells was determined by gating on CD11b+GFP+ doublets, which indicates a CAR-to-target cell binding event. The data shows that sGPC3 blocks the interaction of CAR-expressing macrophages with 15 HEPG2 tumor cells in a dose-dependent manner. Control construct macrophages showed no binding to HEPG2 tumor cells. See, FIG.15B. Human macrophages were plated at 20,000 cells per well and transfected with 9 nM LNP formulated with control mRNA or mRNA encoding an anti-GPC3 CAR construct. Macrophages were incubated overnight. Following overnight incubation, 20 media was exchanged from macrophage wells to remove the remaining LNP. HEPG2 tumor cells expressing target antigen GPC3 and nuclear-localized GFP were added at a density of 10,000 cells/well. Soluble GPC3 was added at various concentrations to the macrophage-tumor cell co-cultures. Imaging of culture over time was done using the IncuCyte Live-Cell Analysis System. 25 The change in fluorescence over time was measured to determine the amount of tumor cell killing that occurred within the co-culture, which was detected via a reduction 209 Attorney Docket No.: 45817-0177WO1 / MTX980.20 in GFP intensity relative to time 0. Calculation of tumor burden was done using the following equation: (Change in Tumor cell Burden = Integrated Intensity of Experimental well (norm. to t=0)/Integrated Intensity of UTD (norm. to t=0)). Macrophages with anti-GPC3 CAR mRNA LNP showed robust HEPG2 cell 5 killing. sGPC3 inhibited CAR macrophage-killing activity in a dose-dependent manner. Control construct macrophages showed no killing of HEPG2 tumor cells. See, FIG.15C. Example 11 Cytotoxic Activity of anti-GPC3 CAR-M is Antigen Density-Dependent The expression of GPC3 on the surface of HEPG2 and HuH-7 was quantified 10 using anti-GPC3 antibody and MESF beads (Bangs Labs). See, FIG.16A. Quantification was done following manufacturer’s protocol. HEPG2 cells expressed ~80,000 (72,830) molecules of GPC3 per cell, while HuH-7 expressed ~20,000 (15,992) molecules per cell. Human macrophages were plated at 40,000 cells per well and transfected with 9 nM LNP formulated with mRNA encoding an anti-GPC3 CAR construct. Macrophages 15 were incubated overnight. Following overnight incubation, media was exchanged from macrophage wells to remove remaining LNP, and HEPG2 or HuH-7 tumor cells expressing target antigen GPC3 were added at a density of 10,000 cells/well. Tumor line was engineered to express nuclear-localized GFP and imaging of culture over time was done using the IncuCyte Live-Cell Analysis System. 20 The change in fluorescence over time was measured to determine the amount of tumor cell killing that occurred within the co-culture, which was detected via reduction in GFP intensity relative to time 0. Calculation of tumor burden was done using the following equation: (Change in Tumor cell Burden = Integrated Intensity of Experimental well (norm.to t=0)/Integrated Intensity of target cells only (norm.to t=0)). Percent 210 Attorney Docket No.: 45817-0177WO1 / MTX980.20 cytotoxicity was calculated by subtracting Change in Tumor Cell Burden at 72 hours from 1 and then multiplying by 100. Calculation of area under the curve (AUC) was calculated for percent cytotoxicity during 0-12h, from the beginning of the killing assay, using GraphPad Prism. 5 CAR macrophages killed both HEPG2 and HuH-7 tumor cells. HEPG2 cells were killed more effectively due to the higher level of antigen expression. See, FIG.16B. AU565 tumor cells expressing nuclear localized GFP were transduced with lentivirus encoding human GPC3. AU565-GPC3 cells were then sorted to obtain clones with various levels of GPC3 expression. AU565-GPC3 cells were stained with anti-GPC3 10 APC antibody and show graded levels of GPC3 expression. See, FIG.16C. Human macrophages were plated at 10,000 cells per well and transfected with 9 nM LNP formulated with anti-GPC3 CAR mRNA. Macrophages were incubated overnight. Following overnight incubation, media was exchanged from macrophage wells to remove remaining LNP, and AU565-GPC3 from Figure 16C were added at a density 15 of 10,000 cells/well (E:T=1:1). Tumor line was engineered to express nuclear-localized GFP and imaging of culture over time was done using the IncuCyte Live-Cell Analysis System. The change in fluorescence over time was measured to determine the amount of tumor cell killing that occurred within the co-culture, which was detected via reduction in 20 GFP intensity relative to time 0. Calculation of tumor burden was done using the following equation: (Change in Tumor cell Burden = Integrated Intensity of Experimental well (norm.to t=0)/Integrated Intensity of target cells only (norm.to t=0)). Percent cytotoxicity was calculated by subtracting Change in Tumor Cell Burden at 72 hours from 1 and then multiplying by 100. 211 Attorney Docket No.: 45817-0177WO1 / MTX980.20 Calculation of area under the curve (AUC) was calculated for percent cytotoxicity during 0-72h using GraphPad Prism. FIG.16D shows the positive correlation between cytotoxicity (AUC) and surface GPC3 expression on AU565-GPC3 tumor cells. The Shapiro-Wilk test was used to assess whether the data follow a normal distribution. 5 See, FIG.16D. Example 12 Anti-GPC3 CAR-M Cytokine Secretion is Antigen Dependent Macrophages transfected with 9 nM of LNP formulated with mRNA encoding an ⍺GPC3 CAR construct or a control mRNA sequence were incubated in wells of a 96-well 10 plate coated with various amounts of immobilized recombinant GPC3 (rGPC3) overnight at 37ºC. After overnight incubation, supernatant was harvested and assessed for secretion of proinflammatory cytokines using 10-plex proinflammatory MSD kits (Mesoscale Discovery). Each MSD assay was performed with supernatants with 20x or no dilution (neat) following the manufacturer’s protocol. Data for TNF-α (FIG.17A) and IL-8 (FIG. 15 17B) are from 20x dilution plates, and IL-6 data (FIG.17C) are from an undiluted (neat) plate. The data show CAR-expressing macrophages secreted proinflammatory cytokines in response to immobilized rGPC3. The level of secretion of each cytokine occurred in a dose-dependent manner, with more immobilized rGPC3 leading to higher levels of 20 cytokine release. Control mRNA macrophages and untransduced macrophages (UTD) showed no cytokine secretion in response to immobilized rGPC3. Example 13 Antigen Stimulation Polarizes CAR-M to an M1-Phenotype Macrophages transfected with 9 nM of LNP formulated with mRNA encoding an25 anti-GPC3 CAR construct or a control mRNA sequence were incubated in wells of a 96- 212 Attorney Docket No.: 45817-0177WO1 / MTX980.20 well plate coated with various amounts of immobilized recombinant GPC3 (rGPC3) for 48 hours at 37ºC. After 48 hours of incubation, cells were harvested from the plate and stained with antibodies to detect levels of M1 and M2 markers via flow cytometry (CD86-PerCp-Cy5.5, CD163-PE, CD206-AF700, LiveDead Aqua, anti-VHH-iF647). 5 The data show that upon antigen stimulation with rGPC3, M1 marker (CD86) expression increased, while M2 markers (CD163, CD206) decreased in only the CAR-M condition, suggesting CAR activation leads to M1 polarization. See, FIG.18. Example 14 Myeloid cells are the primary CAR+ immune cells In Vivo 10 Naïve C57BL/6 mice were injected with 2 mg/kg LNP formulated with mRNA encoding an anti-GPC3 CAR construct.16 hours after LNP injection blood was harvested and centrifuged, followed by lysing of red blood cells. Remaining immune cells were stained with a panel of antibodies to allow for distinguishing of specific immune cell populations. FIGs.19A and 19B show that the CAR expression population is primarily 15 composed of monocytes in the blood. C57BL/6 mice were subcutaneously injected with 250,000 MC38 tumor cells expressing ffLuc and murine GPC3.14 days post tumor cell injection mice were randomized into groups based on tumor size and injected with 1 mg/kg LNP formulated with mRNA encoding an anti-GPC3 CAR construct. Injections of LNP were given 20 weekly for a total of 3 doses. One day after the final LNP injection tumors were harvested from the mice, digested, and stained with a panel of antibodies to allow for distinguishing of specific immune cell populations. FIG.19C shows anti-GPC3 CAR expression is primarily seen in myeloid cells in the tumor. Example 15 213 Attorney Docket No.: 45817-0177WO1 / MTX980.20 In Vivo Anti-GPC3-CAR mRNA/LNP Treatment Leads to Significant Control of Disseminated Tumor Growth Humanized (hCD34) NSG-S mice were I.V. injected with 1 x 10⁶ Panc1 tumor cells engineered to express GPC3 and luciferase. Four days post tumor implantation mice 5 were I.V. injected with either vehicle, Control Construct LNP, or LNP formulated with anti-GPC3 CAR mRNA. LNPs were dosed 2 times per week (2x/wk) for 8 weeks. All LNPs were dosed at 2mg/kg. Mice injected with anti-GPC3 CAR LNP showed reduction in tumor burden as determined by whole body bioluminescence imaging, while those injected with control 10 construct LNP showed tumor outgrowth similar to vehicle alone. See, FIG.20A. The mouse model was set up the same as that in FIG.20A, except that LNP injections were give 1x per week and lasted 5 weeks. FIGs.20B and 20C show that mice injected with anti-GPC3 CAR LNP had reduction in tumor burden as determined by whole body bioluminescence imaging, while those injected with control construct LNP 15 showed tumor outgrowth similar to vehicle alone. In FIG.20C, the Total Flux values for each mouse from Day 3 was used as a base line to calculate % signal increase or decrease at Day 39: [Total Flux (D39) - Total Flux (D3) ]/Total Flux (D 3) *100. FIGs.20E, 20F, and 20G show reduction in liver tumor burden based on ex vivo bioluminescence imaging (FIG.20E) and IHC staining for GPC3 in the liver (FIGs.20F, 20G). Reduction 20 only occurred in mice injected with anti-GPC3 CAR LNP, and not in vehicle or control construct LNP conditions. Example 16 In Vivo Anti-GPC3-CAR mRNA/LNP Treatment Does Not Impact Liver and Kidney Function or Body Weight 214 Attorney Docket No.: 45817-0177WO1 / MTX980.20 Serum was collected from mice at day of takedown and analysis was completed by IDEXX. Data show that the injection of anti-GPC3 CAR LNP does not increase levels of serum biomarkers for liver and kidney function. See, FIGS.21A-C. Note that FIGs. 21A-21C use Construct 4 while FIG.21D uses Construct 8. 5 No adverse events of change in body weight are observed in any group. See, FIG. 21E. 10 215

Claims

Attorney Docket No.: 45817-0177WO1 / MTX980.20 WHAT IS CLAIMED IS: 1. A chimeric antigen receptor (CAR) comprising an anti-human GPC3 VHH comprising a VHH-CDR1, a VHH-CDR2, and a VHH-CDR3 of any one of the sequences set forth in SEQ ID NO:2, 150, or 151, wherein the VHH is connected to a CD28 hinge region and a CD28 transmembrane domain, wherein the CD28 transmembrane domain is connected to a FCεR1γ intracellular T cell signaling domain. 2. The CAR of claim 1, wherein the anti-human GPC3 VHH comprises an amino acid sequence that is at least 80%, at least 85%, at least 90%, at least 95%, or 100% identical to any one of the sequences set forth in SEQ ID NO:2, 150, or 151. 3. The CAR of claim 1 or 2, wherein the CD28 hinge region and the CD28 transmembrane domain comprises an amino acid sequence that is at least 80%, at least 85%, at least 90%, at least 95%, or 100% identical to the amino acid sequence of SEQ ID NO:3. 4. The CAR of any one of claims 1 to 3, wherein the FCεR1γ intracellular T cell signaling domain comprises an amino acid sequence that is at least 80%, at least 85%, at least 90%, at least 95%, or 100% identical to the amino acid sequence of SEQ ID NO:4. 5. The CAR of any one of claims 1 to 4, wherein the CAR comprises an amino acid sequence that is at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical to the amino acid sequence of SEQ ID NO:5. 6. The CAR of any one of claims 1 to 5, further comprising a signal peptide. 216 Attorney Docket No.: 45817-0177WO1 / MTX980.20 7. The CAR of any one of claims 1 to 4, wherein the CAR comprises an amino acid sequence that is at least 80%, at least 85%, at least 90%, at least 95%, or at least 99% identical to the amino acid sequence of SEQ ID NO:6. 8. The CAR of any one of claims 1 to 4, wherein the CAR comprises the amino acid sequence of SEQ ID NO:5. 9. The CAR of any one of claims 1 to 4, wherein the CAR comprises the amino acid sequence of SEQ ID NO:6. 10. A messenger RNA (mRNA) comprising an open reading frame (ORF) encoding the CAR of any one of claims 1 to 9. 11. The mRNA of claim 10, wherein the ORF is at least 75%, at least 80%, at least 85%, at least 90%, at least 91%, at least 92%, at least 93%, at least 94%, at least 95%, at least 96%, at least 97%, at least 98%, at least 99%, or 100% identical to the nucleic acid sequence set forth in SEQ ID NO:8 or SEQ ID NO:9. 12. The mRNA of claim 11, wherein the ORF comprises the nucleic acid sequence set forth in SEQ ID NO:8. 13. The mRNA of claim 11, wherein the ORF comprises the nucleic acid sequence set forth in SEQ ID NO:9. 14. The mRNA of any one of claims 10 to 13, further comprising a 5′ untranslated region (UTR) comprising the nucleic acid sequence of SEQ ID NO:7 or 56. 15. The mRNA of any one of claims 10 to 14, further comprising a 3′ UTR comprising the nucleic acid sequence of any one of SEQ ID NOs:10 to 12 or 141. 16. The mRNA of any one of claims 13 to 15, wherein the mRNA comprises a 5′ terminal cap. 217 Attorney Docket No.: 45817-0177WO1 / MTX980.20 17. The mRNA of claim 16, wherein the 5′ terminal cap comprises a m⁷GpppG2_^OMe, m7G-ppp-Gm-A, m7G-ppp-Gm-AG, Cap0, Cap1, ARCA, inosine, N1-methyl- guanosine, 2′-fluoro-guanosine, 7-deaza-guanosine, 8-oxo-guanosine, 2-amino- guanosine, LNA-guanosine, 2-azidoguanosine, Cap2, Cap4, 5′ methylG cap, or an analog thereof, optionally wherein the terminal cap comprises m7G-ppp-Gm. 18. The mRNA of any one of claims 13 to 17, wherein the mRNA comprises a poly A region. 19. The mRNA of claim 18, wherein the poly A region is at least about 10, at least about 20, at least about 30, at least about 40, at least about 50, at least about 60, at least about 70, at least about 80, at least about 90 nucleotides in length, or at least about 100 nucleotides in length. 20. The mRNA of claim 19, wherein the poly A region is at least about 100 nucleotides in length (SEQ ID NO:117), optionally wherein the poly A-region comprises the sequence set forth in SEQ ID NO:117. 21. The mRNA of claim 20, wherein the poly A-region comprises the sequence set forth in SEQ ID NO:13. 22. The mRNA of any one of claims 13 to 21, wherein all of the uracils of the mRNA are N1-methylpseudouracils. 23. The mRNA of any one of claims 13 to 21, wherein all of the uracils in the mRNA are 5-methoxyuracils. 24. An mRNA comprising any one of the sequences set forth in SEQ ID NOs.: 250, 251, 252, or 253, optionally wherein the mRNA comprises the sequences set forth in SEQ ID NO:253. 218 Attorney Docket No.: 45817-0177WO1 / MTX980.20 25. A polynucleotide comprising an mRNA nucleotide sequence encoding a GPC3 binding CAR protein, comprising from 5′ to 3′ end: (i) a 5′ cap, optionally which comprises m⁷Gp-ppGm; (ii) a 5′ UTR, optionally which comprises the nucleotide sequence set forth in SEQ ID NO: 7 or 56; (iii) an open reading frame encoding a GPC3 binding CAR polypeptide comprising a nucleotide sequence set forth in SEQ ID NO:8 or 9; (iv) a 3′ UTR, optionally which comprises a nucleotide sequence set forth in any one of SEQ ID NOs:10 to 12 or 141; and (v) a poly A tail, optionally which is of about 100 nucleotides in length (SEQ ID NO:117), and further optionally which comprises optionally which comprises the nucleotide sequence set forth in SEQ ID NO:13. 26. A polynucleotide comprising an mRNA nucleotide sequence encoding a GPC3 binding CAR protein, comprising the sequence set forth in any one of SEQ ID NOs.: 200-207, optionally comprising the sequence set forth in SEQ ID NO: 205. 27. A pharmaceutical composition comprising the mRNA of any one of claims 10 to 24 or the polynucleotide of claim 25 or 26, and a pharmaceutically acceptable excipient. 28. A lipid nanoparticle comprising the mRNA of any one of claims 10 to 24 or the polynucleotide of claim 25 or 26. 29. The lipid nanoparticle of claim 28, wherein the lipid nanoparticle comprises an ionizable lipid, a structural lipid, a phospholipid, and a polyethylene glycol (PEG)-modified lipid. 30. The lipid nanoparticle of claim 29, wherein the ionizable lipid is Compound II or a salt thereof. 219 Attorney Docket No.: 45817-0177WO1 / MTX980.20 31. The lipid nanoparticle of claim 29 or 30, wherein the structural lipid is cholesterol. 32. The lipid nanoparticle of any one of claims 29 to 31, wherein the phospholipid is 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC) or 1,2-dioleoyl-sn-glycero-3- phosphoethanolamine (DOPE). 33. The lipid nanoparticle of any one of claims 29 to 32, wherein the PEG-modified lipid is PEG-DMG or Compound I. 34. The lipid nanoparticle of claim 29, wherein the lipid nanoparticle comprises Compound II, Compound I, Compound IV, and Cholesterol, optionally wherein the LNP comprises about 48 mol% of Compound II, about 2 mol % of Compound I, about 11 mol % of Compound IV, and about 39 mol% of cholesterol. 35. The lipid nanoparticle of claim 29, wherein the lipid nanoparticle comprises Compound II, PEG-DMG, Compound IV, and Cholesterol, optionally wherein the LNP comprises about 48 mol% of Compound II, about 1.5 mol % of PEG-DMG, about 11 mol % of Compound IV, and about 39.5 mol% of cholesterol.. 36. The lipid nanoparticle of claim 29, wherein the lipid nanoparticle comprises Compound III, Compound I, Compound V, and Cholesterol. 37. The lipid nanoparticle of claim 29, wherein the lipid nanoparticle comprises Compound III, Compound IV, Cholesterol, Compound I, and Compound V, optionally wherein the LNP comprises about 39.7 mol% of Compound III, about 18.7 mol% of Compound IV, about 3 mol% of Compound I, about 4.1 mol % of Compound V, and about 34.5 mol % of cholesterol. 220 Attorney Docket No.: 45817-0177WO1 / MTX980.20 38. The lipid nanoparticle of claim 34, wherein the mRNA comprises the sequence of SEQ D NO:205. 39. A method for treating a cancer in a human subject in need thereof, the method comprising administering to the human subject an effective amount of the mRNA of any one of claims 10 to 24 or the polynucleotide of claim 25 or 26, the pharmaceutical composition of claim 27, or the lipid nanoparticle of any one of claims 28 to 38. 40. The method of claim 39, wherein the cancer is a GPC3+ solid tumor, optionally selected from the group consisting of hepatocellular carcinoma (HCC) such as relapsed or refractory HCC, pancreatic cancer such as pancreatic ductal adenocarcinoma (PDAC), breast cancer, a squamous cell lung cancer, a head and neck squamous cell cancer, and a lung squamous cell carcinoma (LSCC). 41. The method of claim 39 or 40, wherein the administering is intravenously. 42. The method of any one of claims 39 to 41, wherein administering is once a week, twice a week, three times a week, once every two weeks, once every three weeks, or once every four weeks. 43. The method of any one of claims 39 to 42, further comprising administering a checkpoint inhibitor, optionally wherein the checkpoint inhibitor is a PD-1 inhibitor, a PD-LI inhibitor, a CTLA-4 inhibitor, a LAG-3 inhibitor, or a CISH inhibitor. 44. The method of claim 43, wherein the checkpoint inhibitor is administered as a protein or as an mRNA, optionally wherein the mRNA is formulated in a lipid nanoparticle. 221 Attorney Docket No.: 45817-0177WO1 / MTX980.20 45. The method of any one of claims 38 to 44, further comprising administering an accessory molecule, optionally wherein the accessory molecule is CD40L. 222