While genetic changes such as activating point mutations, or amplification of the MET gene have been identified in a wide range of human cancers, increased activity of the HGF/c-MET pathway is often seen in cancer as a result of physical and chemical changes in the tumor stroma, leading to upregulation of c-MET, or clonal selection of c-MET-expressing cancer cells. The gene discussed is HGF; the disease is neoplasm.