Growth signals from the tumor stroma, such as TGF-β (transforming growth factor) [38–41], EGF (epidermal growth factor), FGF (fibroblast growth factor), PDGF (platelet-derived growth factor), IGF (insulin growth factor) and HGF (hepatocyte growth factor), are responsible for triggering EMT in cancer cells [42–45]. Here, HGF is linked to cancer.