We previously reported that TWIST1 induces the transcriptional activation of mesenchymal genes such as VIM (Vimentin) and SNAI2 (Snail 2) but induces the transcriptional repression of epithelial genes such as CDH1 (E-cadherin) and ESR1 (ERα) in breast cancer cells (Figure 1A). This evidence concerns the gene ESR1 and breast carcinoma.