Hepatocyte growth factor receptor (HGFR), also known as c-Met or mesenchymal-epithelial transition factor (MET), is a receptor tyrosine kinase (RTK) that is overexpressed and/or mutated in a variety of malignancies. HGFR protein is produced as a single-chain precursor, and HGF is the only known ligand. Normal HGF/HGFR signaling is essential for embryonic development, tissue repair, or wound healing, whereas aberrantly active HGFR has been strongly implicated in tumorigenesis, particularly in the development of invasive and metastatic phenotypes. HGFR protein is a multifaceted regulator of growth, motility, and invasion, and is normally expressed by cells of epithelial origin. Preclinical studies suggest that targeting aberrant HGFR signaling could be an attractive therapy in cancer.