Mesenchymal-epithelial transition (MET) of cancer cells was a reverse process of EMT and Cholera Toxin (CTx), a protein complex secreted by the bacterium Vibrio cholerae (37), was able to induce MET in certain breast cancer cell lines such as MDA-MB-468 but not MDA-MB-231 (38). Here, CYP27A1 is linked to breast carcinoma.