GPC3 (glypican 3) is a cell surface-anchored heparan sulfate proteoglycan that serves as a critical therapeutic target for hepatocellular carcinoma (HCC). GPC3 is highly expressed in more than 70% of HCC cases with minimal expression in normal adult tissues, making it an ideal cancer-specific antigen 1. The protein functions as a membrane-associated glycoprotein that regulates multiple signaling pathways and cellular processes 2. GPC3 forms complex structures with other receptors, including octameric complexes with Unc5D receptors that regulate cell migration during development and cancer metastasis 3. Clinically, GPC3 serves as both a biomarker and therapeutic target for HCC, with elevated expression linked to poor prognosis 1. Multiple therapeutic approaches targeting GPC3 have shown promise, including CAR-T cell therapies, antibody-drug conjugates, and immunoPET imaging agents 415. Enhanced GPC3-targeted CAR-T cells co-expressing IL-15 have demonstrated improved expansion and antitumor activity in clinical trials, achieving a 33% response rate in solid tumor patients 4. Novel GPC3-7-19-CAR-T cells that co-express IL-7 and CCL19 have shown superior efficacy by reconstructing the tumor microenvironment and reducing immunosuppressive cell populations 6.