HGF and breast cancer: Similarly, Bendinelli et al. demonstrated that HGF and transforming growth factor (TGF)-β, both of which are enriched in the metastatic bone matrix, regulate the mesenchymal-to-epithelial transition (the opposite of the epithelial-to-mesenchymal transition) of bone metastatic breast cancer cells via the suppression of tumor suppressor Wwox (WW domain-containing oxidoreductase) [52,53].