In another instance, CAF-secreted TGF-β1 increases the aggressiveness of breast cancer cells by activating the TGF-β/Smad signaling pathway, accompanied by enhanced migratory potential, invasiveness, as well as increased expression of mesenchymal markers such as MMP 2 and 9, vimentin, and fibronectin [31]. This evidence concerns the gene TGFB1 and breast cancer.