Immune checkpoint inhibitors interacting with the PD-1/PD-L1 axis were recently approved by the Food and Drug Administration (FDA) based on successful large randomized controlled clinical trials [2] of patients with metastatic melanoma [3, 4], non-small cell lung cancer (NSCLC) [5, 6] and renal cell cancer [7]. Here, PDCD1 is linked to non-small cell lung carcinoma.