In this study, we tested the relationships between platelet size indexes and RP percentage (RP %) and platelet function (exposure of activated GP IIb-IIIa and P-selectin) in cardiovascular patients with coronary heart disease (CHD) or ACS, receiving dual antiplatelet therapy, acetylsalicylic acid (ASA, an inhibitor of cyclooxygenase and thromboxane A2 synthesis) in combination with clopidogrel or ticagrelor (antagonists of P2Y12 ADP receptors), and in the control group consisted of patients with risk factors for CHD, but no CHD/ACS, and free of antiplatelet drugs. The gene discussed is ITGA2B; the disease is coronary artery disorder.