HGF and neoplasm: Considering the function of HGF-c-MET in angiogenesis formation, and the fact that pro-angiogenetic signals were immunosuppressive, many scholars hypothesized there is a direct link between HGF-c-MET induced angiogenesis, its signals, and the immune suppression of the tumor microenvironment in HGF-c-MET positive tumors 26.