It has been reported that nicorandil could augment CFR in patients with angina pectoris and nearly normal coronary arteriograms.[23] Studies have shown that intracoronary nicorandil ameliorated microvascular dysfunction, which was evaluated with IMR, and improved CFR in patients with STEMI undergoing primary percutaneous coronary intervention.[59,60] In addition, nicorandil may improve chest pain symptoms, and regulate plasma NO and ET-1 in the coronary slow flow.[61]. The gene discussed is EDN1; the disease is angina pectoris.