A large variety of drugs, like ipilimumab, nivolumab, pembrolizumab, atezolizumab, durvalumab, and other anti-PD-1 and PD-L1 inhibitors, are already approved by the FDA for the use in many types of cancers, such as colorectal cancer, gastric cancer, hepatocellular carcinoma, melanoma, classic Hodgkin’s lymphoma, and non-small cell lung carcinoma [119,120,121,122,123]. This evidence concerns the gene PDCD1 and cancer.