HGF and cancer: EMT is a critical event in the development of the invasive and metastatic potentials in cancer progression and EMT is initiated by several inducers such as tumor growth factor- β (TGF-β) [24], hepatocyte growth factor (HGF) [25], epidermal growth factor (EGF) and Wnt, through the regulation of Wnt/β-catenin, TGF-β/Smad, and Notch and Hedgehog (Hh) signaling pathways (as reviewed in [26]–[29]).