So far, the FDA has approved seven PD-1/PD-L1 checkpoint inhibitors (nivolumab, pembrolizumab, cemiplimab, dostarlimab, atezolizumab, avelumab, and durvalumab) for non-small cell lung cancer (NSCLC), bladder cancer, oesophageal cancer, melanoma, and other cancer types2,3. This evidence concerns the gene PDCD1 and cancer.