PDCD1 and melanoma: In particular, atezolizumab (anti-PD-L1 mAb), nivolumab(anti-PD1 mAb), and pembrolizumab (anti-PD1 mAb) have already been approved with durable clinical response and prolonged overall survival (OS), reaching clinics for the treatment of melanoma, non-small cell lung cancer (NSCLC), and renal cell carcinoma (RCC) (6, 12).