Up to date, there are five monoclonal antibody drugs Pembrolizumab (Keytruda), Opdivo (Nivolumab), Tecentriq (Atezolizumab), Bavencio (Avelumab), and Imfinzi (Durvalumab) have been approved as PD-1/PD-L1 signal pathway inhibitors for the treatment of melanoma, non-small cell lung cancer and other diseases198–202 (Table 5). This evidence concerns the gene PDCD1 and melanoma.