At the endpoint of the animal experiment, the tumor volumes in the mice treated with PD-1-deficient GPC3-CAR T cells were significantly (P < 0.05) smaller than those treated with wild-type GPC3-CAR T cells, and tumor weights in the mice treated by the PD-1-deficient GPC3-CAR T cells were significantly (P < 0.01) lighter than those in other groups (Supplementary Figure S2), indicating that the disruption of PD-1 enhanced the anti-tumor activity of GPC3-CAR T cells. Here, PDCD1 is linked to neoplasm.