Additionally, mesenchymal stem cells promote metastasis by enhancing generation of new blood vessels. Mesenchymal stem cells have the capacity to differentiate into endothelial cells and to create a capillary network. Injected mesenchymal stem cells migrate to the metastatic sites and produce pro-angiogenic factors: vascular endothelial growth factor, basic fibroblast growth factor, TGF-β, platelet-derived growth factor, IL-6, monocyte chemotactic protein-1, HGF, resulting with neo-vasculirization.