Among its subtypes, triple-negative breast cancer (TNBC), distinguished by the absence of estrogen receptors (ER), progesterone receptors (PR), and human epidermal growth factor receptor 2 (HER2) expression, denotes one of the most aggressive forms of BC and is marked by rapid recurrence, early metastasis, and a bleak prognosis (3–5). Here, ESR1 is linked to breast cancer.