The pathological histological examination findings were: ductal carcinoma in situ (DCIS) of intermediate nuclear grade, 3 mm in greatest dimension, histological grade II (3 + 3 + 1 = 6), ER (+), PR (+), HER2 (2+) (no amplification by FISH), ki-67 3%, pT1cN1M0, and pStage IIA. The gene discussed is ESR1; the disease is ductal breast carcinoma in situ.