As an example, aromatase inhibitors – which suppress estrogen serum levels and are currently approved as a treatment of (hormone-receptor positive) breast cancer in premenopausal (in addition to a GnrRH analog) and postmenopausal women and in men and gynecomastia in men [154] – might theoretically be an attractive treatment option in men with chronic migraine. The gene discussed is CYP19A1; the disease is breast cancer.