In recent years, therapeutic antibodies (Abs) against PD-L1 (e.g., atezolizumab, avelumab, and durvalumab) and PD-1 (e.g., nivolumab, pembrolizumab, spartalizumab, and cemiplimab) have been shown to reactivate T cell immunity in the tumor microenvironment, leading to the elimination of tumor cells and remarkable survival benefits in various advanced cancers [14,15,16,17]. This evidence concerns the gene PDCD1 and cancer.