Subsequently, the application of Cas9-edited PD-1 in CAR T cells has been progressively implemented in clinical trials such as phase I clinical trials of multiple myeloma with mesothin-positive solid tumors (NCT03545815), multiple myeloma (NCT03399448), esophageal cancer (NCT03081715), metastatic NSCLC (NCT02793856), EBV (Epstein-Barr virus)-positive advanced stage malignancies (NCT03044743), advanced hepatocellular carcinoma (NCT04417764) and engineered TILs/CAR-TILs to treat advanced solid tumors (NCT04842812). Here, PDCD1 is linked to plasma cell myeloma.