HGF and neoplasm: MSCs may secrete several different types of mediators including interleukin-10 (IL-10)[17], transforming growth factor-β (TGF-β)[17,18], hepatocyte growth factor (HGF)[18], and vascular endothelial growth factor (VEGF)[19] when exposed to inflammatory cytokines, which has been reported to play an important role in tumor development.