CD80 and neoplasm: Especially, programmed death-ligand 1 (PD-L1), also known as B7-H1 or CD274, is expressed on tumor cells and immune cells; it suppresses T cell migration, proliferation, and secretion of cytotoxic mediators, and it also restricts tumor cell killing through binding to programmed death-1 (PD-1) and B7.1 (CD80) [8].