Many different monoclonal antibodies (mAb) targeting CTLA-4, PD-1, or PD ligand (PD-L)1, such as ipilumumab and nivolumab, pembrolizumab, atezolizumab, durvalumab and avelumab, have been approved for the treatment of specific cancers [25,38,39]. This evidence concerns the gene CTLA4 and cancer.