P2RY1 and ischemic stroke: Our previous studies have shown that genetic variants in cytochrome P450 (CYP), platelet membrane receptor (P2Y12, P2Y1), and glycoprotein IIIa (GPIIIa) genes are associated with the efficacy of clopidogrel and adverse clinical events on ischemic stroke (IS) patients in a Chinese population [4, 5].