Cases are typically divided into three pathological categories: estrogen receptor (ER) and progesterone receptors (PR)-positive cases, human epidermal growth factor 2 (HER2)-positive (overexpressing) cases, and lastly triple negative breast cancers (TNBC), so named because of deficiency of ER and/or PR expression, along with lack of HER2 overexpression 3. Here, ESR1 is linked to triple-negative breast carcinoma.