HGF and cancer: In most of cancers, various growth factors and their receptors are overexpressed, such as the basic fibroblast growth factor (bFGF) [1-3], epidermal growth factor (EGF) [4], platelet-derived growth factor (PDGF) [5,6], hepatocyte growth factor (HGF) [3,7] and vascular endothelial growth factor (VEGF) [8].