CTLA4 and neoplasm: This anti-tumor immune response can be counterbalanced by inhibitory signaling pathways including immune checkpoint receptors (ICPs), and their ligands such as the programmed death receptor-1 (PD-1) or cytotoxic T lymphocyte-associated protein 4 (CTLA4) pathways [7,8], that can be blocked by specific antibodies defined as immune checkpoint inhibitors (ICIs).