Several clinical trials carried out in the past two years had revealed that both anti-PD-1 antibodies (such as Nivolumab, Pidilizumab, and Pembrolizumab) and anti PD-L1 antibodies (such as MPDL3280A) had shown significant antitumor effects in patients with metastatic melanoma [40], Hodgkin's lymphoma [16], bladder cancer [41], and lung cancer [42]. This evidence concerns the gene PDCD1 and metastatic melanoma.