These findings suggested that during the early stages of limb ischemia, SDF1α-eMSCs were involved mainly in the process of arterialization (defined as remodeling of preexisting collateral arteries to generate larger conductance vessels) but not in de novo vasculogenesis (defined as recruiting endothelial progenitor cells to foci of neovascularization where they form new blood vessels in situ). Here, CXCL12 is linked to limb ischemia.