Improvements in this area consist of FDA approval for monoclonal antibodies of programmed death-1 (PD-1), cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4), and programmed death-ligand-1 (PD-L1) for the treatment of small-cell lung cancer, advanced melanoma, and metastatic bladder cancer. This evidence concerns the gene CTLA4 and melanoma.