Clinically, it has been utilized to also determine the prognosis of postmenopausal women with ER+ and LN ± disease of stages 1 or 2 (Parker et al., 2009; Nielsen et al., 2010) Although ample work has been done on the discovery of the biomarkers for BC’s diagnosis, progression, and treatment end point, further investigations are required to identify the biomarkers for diverse forms of the breast cancer. The gene discussed is ESR1; the disease is breast cancer.