Studies have indicated that the development of immune check point inhibitors (ICIs), such as antibodies against the cytotoxic T-lymphocyte antigen CTLA-4 (8), targeted immunotherapies in the pathways of programmed cell death 1 (PD-1) and programmed death-ligand 1 (PD-L1) antibodies, have transformed the treatment paradigms of a variety of solid tumors by efficiently killing cancer cells through activation of the immune response (8). Here, PDCD1 is linked to cancer.