Monoclonal antibodies (mAbs) might be one of the alternative methods for cancer therapy [46,47], given that mAbs bind specifically to a target protein located on cancer cells but independently of its active pocket, and some mAbs work through different mechanisms to inhibit immune checkpoints such as cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) or programmed cell death 1 (PD-1) [2]. This evidence concerns the gene PDCD1 and cancer.