In turn, breast cancer can be classified into different subtypes depending on the expression pattern of some receptors, such as estrogen (ER), progesterone (PR) and human epidermal growth factor type 2 (Her-2), giving rise to luminal breast cancer A (ER+, PR+), luminal B (ER+, PR+), Her-2 positive and triple negative marker. Here, ESR1 is linked to breast carcinoma.