CXCR4 and coronary artery disorder: SDF-1α, a chemokine protein of CXCL12, not only plays a beneficial role in the mobilization of EPCs from the bone marrow to circulation and homing of EPC to the ischemic area for angiogenesis through CXCR4-dependent mechanism [28, 29], but also is associated with an increased risk of CAD via leukocyte activation and proinflammatory stimulation [30].