TGFB1 and breast cancer: The continuous downregulation of miR-1199-5p expression during a TGFβ-induced EMT was due to transcriptional repression as determined by a miR1199-promoter/luciferase-reporter assay during a TGFβ-induced EMT in NMuMG/E9 cells and Py2T murine breast cancer cells, and in mesenchymal Py2T cells and metastatic 4T1 murine breast cancer cells treated with TGFβ for >20 days (Fig. 2a, Supplementary Fig. 3a, b).