ESR1 and triple-negative breast carcinoma: Triple-negative breast cancer (TNBC) has been evolved as most aggressive type of BC (Vagia et al. 2020) due to its lack of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER-2), resulting in un-responsiveness towards endocrine therapy or anti-HER2 treatment (Vagia et al. 2020).