Since then, several immune-based therapies that mediate checkpoint inhibition have been approved for the treatment of advanced melanoma, including antibodies designed to block cytotoxic T-lymphocyte-associated protein 4 (CTLA4; ipilimumab) and programmed cell death protein 1 (PD-1; nivolumab and pembrolizumab) [4]. This evidence concerns the gene PDCD1 and melanoma.