CXCL12 and cancer: In a rat glioma model, C6 cancer stem cells showed increased expression of VEGF and SDF1 versus non-CSCs, suggesting that these cells can initiate angiogenesis, the formation of new blood vessel from pre-existing ones and SDF1-mediated vasculogenesis, the de novo formation of blood vessels, by recruiting endothelial progenitor cells to the tumor bed [87].