To date, immune-checkpoint blockade (ICB) therapies targeting cytotoxic T lymphocyte-associated antigen 4 (CTLA4/CD152), programmed cell death protein 1 (PD-1/CD279), and programmed death-ligand 1 (PD-L1) have presented unprecedented responses in significant percentages of cancer patients [1]. This evidence concerns the gene CTLA4 and cancer.