TGFB1 and breast cancer: We validated these findings in TGFβ-treated HMLE mammary epithelial cells (Supplementary Figure S5B) and additionally found that mesenchymal breast cancer cell lines MDA-MB-231 and Hs578t cells have a lower CTCF protein expression than epithelial breast cancer cell lines MCF7 and SKBR3 (Figure 4F).