MicroRNAs (miRs) are post-transcriptional inhibitory regulators of gene expression that bind to complementary messenger RNA transcripts. miRs have recently come into focus of cardiovascular research. Because each miR can repress many target mRNAs, it is possible that dysregulation of a single miR might play important roles in complex pathological situations. Our laboratory focuses on the identification of miRs which are involved in ischemic disease and/or post-ischemic vascular repair. We have reported for the first time the importance of miR-503 in diabetes mellitus–associated ischemic disease. miR-503 represses cell cycle–associated genes in endothelial cells. Moreover, new evidences suggest a role of miR-503 in the endothelial cell/pericyte cross-talking. I will present on miR-503 as well as touch on other miRs, which we are elucidating to be relevant for post-ischemic vascular repair. Bone marrow-derived proangiogenic cells (PACs) contribute into post-ischemic vascular repair. We have profiled miR expression in PACs harvested from the peripheral blood of human patients with critical limb ischemia (CLI) and with/out diabetes (controls: healthy donors) and found that member of the extended miR-16 family are deregulated in CLI, thus impairing the PAC capacity to migrate toward proangiogenic stimuli. However, this defect can be corrected ex-vivo by miR therapeutics to enhance the regenerative potential of PACs once transplanted in immunocompromised mice with limb ischemia. Finally, I may be able to present additional data on miR expression in a series of different clinical samples.