P2RY12 (P2Y12) is a G-protein coupled receptors, belonging to a family with different pharmacological selectivity for various adenosine and uridine nucleotides. This receptor is involved in platelet aggregation and is a target of antagonists for platelet inhibition in the treatment of coronary artery and cerebrovasular disease, thromboembolisms and other clotting disorders. In the brain, mediates microglia chemotaxis as part of closure of the blood-brain barrier following breakdown from injury. Mutations in this gene are implicated in bleeding disorder, platelet type 8 (BDPLT8). In immunohistochemistry, P2RY12 has membranous and cytoplasmic positivity in the amygdala, on small neurons of the caudate nucleus populations of nuclei in the medula, on astrocytes and in the posterior pituitary. In peripheral tissues, P2RY12 stains platelet pellets, bone marrow megakaryocytes, pancreatic islets, some lung pneumocytes, the bladder epithelium, gastrointestinal neuroendocrine cells, and Leydig cells of the testis. References: Proc Natl Acad Sci U S A. 2016 Jan 26; 113(4): 1074–1079, PMID: 26755608;