CTLA4 and neoplasm: Immunotherapy has focused on augmenting cell-mediated immunity with a biological anti-tumor cell response, and involves the use of antibodies against cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) and against the programmed death-1 (PD-1) and its ligands such as PD-L1 and PD-L2 [87].