This process primarily targets two major signaling pathways, allowing for tumor cell immune evasion, namely: (1) programmed cell death protein 1 (PD1)-programmed death-ligand 1 (PD-L1); and (2) cytotoxic T-lymphocyte associated protein 4 (CTLA4)-B7 [22]. The gene discussed is CTLA4; the disease is neoplasm.