This new model, to be used only in those practices in which biomarker assessment is routinely performed for breast cancer, combines the classic anatomic TNM staging with tumor grade and the status of three important prognostic factors, namely human epidermal growth factor receptor 2 (HER2) and two hormonal receptors (ER (estrogen receptor) and PR (progesterone receptor)) [14]. Here, ESR1 is linked to breast cancer.