CTLA4 and neoplasm: To date, this type of immunotherapy is based almost exclusively on the restoration of anti-tumor immunity, resulting from the blockade of one or both of two distinct types of ICI proteins, viz., cytotoxic T-lymphocyte-associated protein-4 (CTLA-4; also known as CD152) (3) and programmed cell death protein-1 (PD-1; CD279) (4), which affect different stages and mechanisms of effector T cell activation (5, 6).