The first anti-PD-1 inhibitor nivolumab (BMS-936558 or MDX1106), a fully human IgG4 monoclonal antibody, manufactured by Bristol-Myers Squibb, was approved by FDA in 2014, and proved that be effective in several cancers, like melanoma (42), advanced nonsquamous non-small-cell lung cancer (NSCLC) (43), squamous NSCLC (44), advanced renal cancer carcinoma (14), relapsed or refractory Hodgkin’s lymphoma (45) and so on. Here, PDCD1 is linked to cancer.