In this context, several mAbs targeting PD-1 and PD-L1 ICPs, including nivolumab, pembrolizumab, avelumab, and durvalumab, have been approved by the FDA as clinical immunotherapies for various types of cancer, such as metastatic melanoma, NSCLC and metastatic Merkel cell carcinoma (MCC) [163]. The gene discussed is PDCD1; the disease is cancer.