ESR1 and triple-negative breast carcinoma: Triple-negative breast cancer (TNBC) is an entity that tests negative for the expression of the estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (Her-2), it is characterized by low differentiation, high invasiveness, a propensity for local and distant metastases, poor prognosis, and high recurrence rates [1].