PDCD1 and cancer: Both PD-1-targeting monoclonal antibodies (mAbs; nivolumab, pembrolizumab, cemiplimab, and dostarlimab) and PD-L1-targeting mAbs (atezolizumab, avelumab, and durvalumab) have demonstrated therapeutic efficacy in various cancer types and achieved U.S. Food and Drug Administration (FDA) approval (8).