KDR and peripheral arterial disease: The circulating EPCs, defined as CD34+KDR+ cells, are reduced in the presence of classical risk factors for CVD, such as diabetes, smoking, hypercholesterolemia, and hypertension (1, 26, 30), as well as in the context of the three common manifestations of established coronary artery disease (CAD), cerebrovascular disease, and peripheral artery disease (PVD) (1, 31–33).