P2RY12 encodes a G-protein coupled purinergic receptor that responds to ADP and ATP to inhibit adenylyl cyclase signaling. The receptor is critical for normal platelet aggregation and blood coagulation, with genetic variants associated with bleeding disorders 1. Beyond its established role in hemostasis, P2RY12 serves as a key microglial marker involved in neuroinflammation and brain homeostasis 2. In microglia, P2RY12 regulates cell motility and migration, representing the initial steps of neuroinflammation 2. The receptor shows age-dependent expression changes, with downregulation observed in aged microglia across multiple species, contributing to compromised immune responsiveness 3. In Alzheimer's disease, P2RY12 expression patterns are altered, with loss of P2RY12-positive phenotypes observed around β-amyloid plaques 4. P2RY12 also contributes to vascular pathology by promoting foam cell formation through inhibition of autophagy via PI3K-AKT-MTOR signaling in vascular smooth muscle cells 5. Clinically, P2RY12 polymorphisms influence clopidogrel treatment outcomes in coronary artery disease patients and IVIG resistance in Kawasaki disease 16.