c-Met (also named MET or HGFR) is a receptor tyrosine kinase that transduces signals from the extracellular matrix into the cytoplasm by binding to the HGF ligand. c-Met regulates many physiological processes including proliferation, scattering, morphogenesis, and survival. The primary single-chain precursor protein is post-translationally cleaved to produce the alpha and beta subunits, which are disulfide-linked to form the mature receptor. Overexpression and/or mutation of c-Met has been reported in various human malignancies, including lung cancer, breast cancer, head and neck cancer, gastric cancer, colorectal cancer, bladder cancer, uterine cervix carcinoma, esophageal carcinoma, c-Met could serve as an important therapeutic target . The c-met receptor is a 190-kD glycoprotein consisting of a 145-kD membrane-spanning beta chain and a 50-kD alpha chain .