HGF R, also known as Met, is a glycosylated receptor tyrosine kinase that plays a pivotal role in epithelial morphogenesis and cancer development. It is synthesized as a single-chain precursor, which undergoes cotranslational proteolytic cleavage to form a mature HGFR. This mature receptor is a disulfide-linked dimer consisting of a 50 kDa extracellular alpha chain and a 145 kDa transmembrane beta chain. The extracellular domain （ECD） features a seven-bladed beta-propeller sema domain, a cysteine-rich PSI/MRS domain, and four Ig-like E-set domains. The cytoplasmic region contains the tyrosine kinase domain. HGFR is typically expressed by cells of epithelial origin, while HGF expression is limited to cells of mesenchymal origin.