Methods: The proposed study is a prospective one, and will be held on consecutive individuals undergoing the non-invasive brachial artery flow-mediated dilation (FMD) ultrasound for endothelial function at the endothelial function laboratory of the Sheba Medical Center. The study group will be divided into healthy subjects group and coronary artery disease (CAD) patients group, both of which will be analyzed in respect to age, cardiovascular risk factors and the results of the platelet and endothelial functions tests. The association between platelet and endothelial functions will be then assessed in the healthy subjects group and in the CAD patients group.