PDCD1 and cancer: Nivolumab is the first PD-1 blocking mAb for the treatment of NSCLC, which significantly improves objective remission rate and overall survival compared with traditional chemotherapy (Borghaei et al., 2015), especially in patients with PD-L1 expression ≥50% in cancer cells, so nivolumab was approved by the FDA in 2015 for the treatment of metastatic NSCLC (Cortinovis et al., 2016) (Table 1).