PDCD1 and cancer: Immunotherapies targeting PD-1 or PD-L1 that have had tremendous clinical efficacy in many cancer types and have been approved by the Food and Drug Administration (FDA) include pembrolizumab (Keytruda), nivolumab (Opdivo), and cemiplimab (Libtayo) as anti-PD-1 antibodies, and avelumab (Bavencio), durvalumab (Imfinzi), and atezolizumab (Tecentriq) as anti-PD-L1 antibodies [8].