CXCL12 and limb ischemia: Because intramuscular transplantation of SDF1α-eMSCs significantly improved blood perfusion and limb salvage beginning three days after ischemic insult, we addressed the role of SDF1α-eMSCs in the early stages of limb ischemia during which vascular remodeling and muscle regeneration occur using tissue harvested 7 days after Dil-labeled cell transplantation.