Subsequently, enhanced antitumor function was demonstrated using interrupted PD-1 signaling in combination with adoptive CAR T cell therapy, such as PSCA-BBZ/PD1CD28 CAR-T41 and bi-specific Trop2/PD-L1 CAR-T42 targeted against prostate cancer and gastric cancer, respectively, which claimed to improve the killing effect of CAR T cells in solid tumors. This evidence concerns the gene PDCD1 and gastric cancer.