HGF and neoplasm: MET mutations could result in the abnormal expression of MET axis, and the MET/HGF (hepatocyte growth factor) signal pathway play an important role in the MET axis, and this signal pathway leads to tumor cell migration, invasion, and metastasis (17) and are associated with resistance to treatment with EGFR and vascular endothelial growth factor receptor (VEGFR) inhibitor.