Mesenchymal epithelial transition factor （c-MET） is a proto-oncogenic receptor tyrosine kinase. The endogenous ligand for c-MET is HGF （hepatocyte growth factor）， which is a disulfide-linked heterodimeric molecule produced predominantly by mesenchymal cells. In the adult， c-MET protein expression is limited to stem and progenitor cells and is required for wound healing and hepatocyte regeneration. In the embryo， c-MET receptors are expressed on cells of epithelial origin， which are vital for invasive growth and mediate epithelial-mesenchymal transition （EMT）. Abnormal activation of the HGF/MET pathway leads to a variety of cancers. c-MET mutation is linked with a poor prognosis since it can trigger tumor growth， angiogenesis and metastasis.
