The employment of the immunohistochemical method within the defined boundaries of the laboratory, verified by the highly regarded American Society of Clinical Oncology, has indisputably confirmed that the existence of human epidermal growth factor receptor 2 (HER2), estrogen (ER) and progesterone (PR) is universally perceived among individuals affected by the formidable and widespread forms of breast cancer that demonstrate both aggressive and metastatic attributes (8). Here, ESR1 is linked to breast cancer.