Immunostaining revealed estrogen receptor (ER) (−), progesterone receptor (PgR) (−), human epidermal growth factor receptor-2 (HER2) (0–1+), and Ki-67 (<3%) expression in the pleomorphic adenoma region, and ER (−), PgR (−), HER2 (2+), Ki-67 (15%), and AR (+) in the DCIS region (Fig. 4). The gene discussed is ESR1; the disease is ductal breast carcinoma in situ.