It should be mentioned in the case of the breast cancer cell lines used in this study, the distinction could also be between Estrogen Receptor alpha (ERα)-negative (MDA-MB-231 and MDA-MB-436) and ERα-positive (MCF-7, BT-474) breast cancer cells and also on the basis of Epithelial Mesenchymal Transition (EMT), with MDA-MB-231 and MDA-MB-436 cells which have undergone EMT. Here, ESR1 is linked to breast cancer.