It has been recently demonstrated that the knockdown of ERα in ERα(+) MCF-7 breast cancer cells (MCF-7/SP10+) induced profound morphological changes, including mesenchymal characteristics such as elongated shape, numerous cytoplasmic protrusions (filopodia and lamellipodia) and the ability to grow distant to each other (Fig. 1a, image C). This evidence concerns the gene ESR1 and breast cancer.