CTLA4 and cancer: Over the past decade, therapeutic approaches have utilized the cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) (207) or programmed death 1 (PD-1)/programmed death receptor ligand-1 (PD-L1) (208) blocking antibodies, which have yielded notable response rates and have shown a remarkable clinical response in patients with advanced cancer.