In support of our previous work, others have demonstrated, using in vitro studies, that tumour-associated myoepithelial cells secrete TGFβ to promote the invasive progression of DCIS cells due to enhancing epithelial-to-mesenchymal transition and basal-like phenotypes through activation of the TGFβ/SMAD signalling pathway37,38. This evidence concerns the gene TGFB1 and ductal breast carcinoma in situ.