@@ Microvesicles (MV), also known as microparticles, are small membranous structures that are released from cells upon activation or during apoptosis. Many cell types have been shown to release MVs, including circulating platelets, leukocytes, and erythrocytes, as well as cells of the vascular wall, mainly endothelium, macrophages, and smooth muscle cells. MVs are generally identified based on size (forward scatter) and surface exposure of phosphatidylserine (PS, specifically binding with fluorescently labeled annexin V). Tissue factors (TF), an initiator of extrinsic coagulation pathway, were classically thought to expose to circulation when vascular wall injured or ruptured. Recent studies showed that TF may also exist in circulation and carried by MVs. Increased plasma levels of MVs have been reported in occluded coronary arteries of the AMI before the angioplasty, or in the peripheral blood in patients with hyperlipidemia, hypertension, diabetes, and the metabolic syndrome. High levels of circulating MVs predict subclinical atherosclerosis burden in asymptomatic subjects. In addition, MVs have also been detected within human atherosclerotic plaques. A potential pathogenic role for MVs in the development and progression of atherosclerosis, however, remains understudied. The local stimuli that provoke MV generation within atheromata have not been defined, and their local, pro-atherogenic effects are only now beginning to be explored.