Although Sumi M et al. also showed that reconstituted HDL-C directly stimulates endothelial progenitor cell differentiation via phosphatidylinositol 3-kinase/Akt pathway and enhances ischemia-induced angiogenesis, we did not find HDL-C was associated with coronary collateral development in this population study [17]. This evidence concerns the gene AKT1 and ischemia.