This article discusses the relationship between coronary artery disease and circulating endothelial progenitor cells. Infusions of EPCs are shown to promote postnatal neovascularization after myocardial infarction in animal models, and the reduction of EPC numbers can be counteracted by 3-hydroxy-3-methylglutaryl coenzymeA (HMG-CoA) reductase inhibitors (statins), vascular endothelial growth factor (VEGF), estrogen, or exercise.