Immune checkpoints constitute a complex array of receptors (e.g., PD-1, CTLA-4) and their ligands (e.g., PD-L1/PD-L2, CD80/C86) expressed on both innate and adaptive immune cells, which exert key regulatory roles during homeostasis and inflammatory pathologies, mainly in chronic infection, sepsis and cancer. Here, CD274 is linked to cancer.