Immune checkpoint blockade (ICB) therapies such as PD-1, PD-L1, and CTLA-4 inhibitors, which are now recognized as a potential treatment strategy, have proven to be extremely effective to prolong the survival time of various advanced tumors like bladder cancer, lung cancer, breast cancer, and cutaneous melanoma (14, 24–26). Here, PDCD1 is linked to cutaneous melanoma.