GPC3 and hepatocellular carcinoma: To further investigate the effect of PD-1-mediated immunosuppressive pathway on the efficacy of GPC3-CAR T cells against HCC, the PD-1-deficient GPC3-CAR T cells was generated through direct delivery of CRISPR/Cas9 gene-editing system into the CAR T cells by electroporation on day 3 post-lentiviral transduction.