ESR1 and breast cancer: Moreover, we integrated prognostic features, including age, T (tumor size), N (node status), M (metastasis), stage, ER (estrogen receptor), PR (progesterone receptor), HER2 (human epidermal growth factor receptor-2), and risk score, and developed the comprehensive nomogram to predict 1-, 3-, and 5-year OS of BC patient (Figure 1H).