KDR and type 1 diabetes mellitus: At the clinical side, metformin increased cEPCs levels (CD45dimCD34+KDR+) in T1DM patients while reduced the number of circulating endothelial cells (cECs; CD45dim CD133− CD34+ CD144+ KDR+) and augmented the in vitro formation of colonies and the adhesion of pro-angiogenic cells to fibronectin [169].