Triple-negative breast carcinoma (TNBC) is a subtype of breast carcinoma with hormone receptor immunohistochemistry (IHC) stains of less than 1% for estrogen receptors (ER) and progesterone receptors (PR) and is devoid of HER2 protein overexpression or HER2 gene amplification (or both) (Bergin and Loi, 2019). Here, ESR1 is linked to breast carcinoma.