GPC3 and hepatocellular carcinoma: Furthermore, IL-15 and IL-21 armored anti-GPC3 CAR-T cells have progressed to several ongoing phase I clinical trials against GPC3 + pediatric solid tumors (NCT04377932, NCT04715191), hepatocellular carcinoma (NCT05103631), neuroblastoma (NCT03721068), and osteosarcoma (NCT03721068).