Approved ICIs in the form of monoclonal antibodies against cytotoxic T-lymphocyte–associated antigen 4 (CTLA-4), programmed cell death protein 1 (PD-1), or its ligand PD-L1 have enhanced clinical responses in patients with advanced melanoma, lung, kidney, bladder cancer; however, limited response rates were evident in many other patients due to primary or acquired resistance [2, 3]. This evidence concerns the gene PDCD1 and melanoma.