Used as a recombinant protein antigen in immunoassay development and antibody screening, particularly for cancer research targeting hepatocellular carcinoma. Serves as a critical tool in the development of GPC3-specific immunotherapies, including CAR-T cells and monoclonal antibodies, due to its high expression in liver cancer and minimal presence in healthy tissues. Commonly employed in ELISA, Western blot, and flow cytometry to validate antibody binding and specificity. Also utilized in structural studies to map epitopes and understand protein-ligand interactions involved in tumor growth regulation.