HGF and neoplasm: Signaling pathways, such as the epithelial growth factor receptor (EGFR) and Ras, mammalian target of rapamycin, insulin-like growth factor receptor 1, hepatocyte growth factor and c-Met, Wingless, and angiogenesis, were, even if not entirely, involved in the complex and interactive system that formulates this hypervascular tumor entity [38].