The resounding achievements observed in clinical trials have paved the way for the Food and Drug Administration (FDA) approval of ten PD-1 monoclonal antibodies (including nivolumab, pembrolizumab, camrelizumab, sintilimab, cemiplimab, prolgolimab, tislelizumab, dostarlimab, toripalimab, and zimberelimab) and three PD-L1 monoclonal antibodies (namely avelumab, durvalumab, and atezolizumab) to combat various forms of cancer [28]. Here, PDCD1 is linked to cancer.