ESR1 and triple-negative breast carcinoma: This disease is characterized by enormous heterogeneity and classified concerning the presence or absence of these receptors as luminal A (estrogen receptor, ER, and/or progesterone receptor, PR positive, and human epidermal growth receptor 2, HER2 negative), luminal B (ER and/or PR positive and HER2 positive), HER2-enriched (ER and PR negative and HER2 positive), and basal-like (triple negative breast cancer-ER, PR, and HER2 negative) [2].