CD80 and neoplasm: This field spans from cytokine therapy, tumor vaccines, and infusions of primed T-cells to drugs specifically targeting immune checkpoint signaling such as programmed cell death 1 (PD1/CD279) and its ligand PDL1 and the cytotoxic T-lymphocyte-associated protein 4 (CTLA4/CD152) and its ligand B7, both ligands being expressed on target- or antigen-presenting cells to inhibit T-cell activation.