ESR1 and triple-negative breast carcinoma: Eleven (39%) patients had the estrogen receptor (ER)+/human epidermal growth factor receptor 2 (HER2) negative subtype, 7 (25%) had the triple-receptor negative breast cancer (TNBC) subtype, 6 (21%) had the HER2 subtype, and 4 (14%) had the ER+/HER2+ subtype.