Many ongoing clinical trials are evaluating the efficacy of PD-1 deficient T cells/CAR-T cells in patients with solid tumors or hematological cancers (NCT03545815, NCT03525782, NCT03298828, NCT03525652, NCT02793856, NCT03081715, NCT03399448, NCT02867332, NCT03044743, NCT03030001, NCT02863913, NCT03747965, NCT03706326, ChiCTR1800020306, ChiCTR1800018713, ChiCTR1900022620, ChiCTR-OIC-1701131, ChiCTR-OIN-17012136, ChiCTR1800016023, ChiCTR1900025088, NCT03208556 and NCT04213469) (Table 10 for clinical tials on solid tumors). Here, PDCD1 is linked to hematopoietic and lymphoid cell neoplasm.