The anti-PD-1 antibodies nivolumab and pembrolizumab have demonstrated better safety profiles and far greater success rates in comparison to current standard treatments (such as sorafenib to treat advanced hepatocellular carcinoma, HCC) [110] and also in comparison to anti-CTLA-4 strategies [54] in several clinical trials for different cancers [111, 117, 118]. This evidence concerns the gene CTLA4 and cancer.