Since the clinical efficacy of DAPT as compared with OAC was established in RCTs in the late 1990s, DAPT consisting of aspirin and a P2Y12 inhibitor has been the cornerstone of antithrombotic management in patients undergoing PCI,3 while OAC with vitamin K antagonist (VKA) was superior over DAPT in reducing ischemic events among patients with AF.4 The gene discussed is P2RY12; the disease is atrial fibrillation.