HGF and ductal breast carcinoma in situ: In addition to promoting cell proliferation of breast cancer cells, the paracrine HGF/c-MET signaling between fibroblasts and pre-invasive ductal carcinoma in situ cells (DCIS) enhances the transition to invasive carcinomas improving their ability to migrate, degrade collagen type IV, and to express and secrete uPA and uPAR [57].