Although we did not find any significant changes in CYP11A1 and CYP1B1 expression in the breast tissue of the metformin-treated group, it has been reported that metformin is able to directly reduce the protein levels of CYP11A1 in the ovary granulosa cells83 and CYP1B1 in breast cancer cells84. The gene discussed is CYP11A1; the disease is breast carcinoma.