The MES/MSL subtype displays the characteristics of epithelial–mesenchymal transition (EMT) and breast cancer stem cells (CSCs) and is therefore enriched in pathways crucial for the maintenance of these phenotypes: transforming growth factor beta (TGF-β), Notch, Wnt/β-Catenin and Janus kinase/signal transduction and transcription activation (JAK/STAT) pathways, showing the possibility of utilizing this axis for targeted therapy [5,7,9]. This evidence concerns the gene TGFB1 and breast cancer.