Considering that > 70% of AR expression is consistent between primary and metastatic breast cancers, AR may be a novel diagnostic and therapeutic target for patients with AR-positive breast cancer.33 In luminal mammary carcinomas, a high percentage of cases express androgen receptors (AR), and the ratio of AR to estrogen receptors (ER) or progesterone receptors (PR) is considered a potential prognostic factor. The gene discussed is ESR1; the disease is breast cancer.