ESR1 and breast cancer: To plan adequate therapy in patients with early breast cancer (Fig. 2), pathology reports should include in all cases the expression and levels of ER, PR, HER2, and Ki-67, in addition to histological grade (as well as BRCA in high-risk HR-positive, HER2-negative patients, and TNBC) to assist prognosis and to establish current therapeutic options available, including hormone therapy, chemotherapy, anti-HER2 therapy and PARP inhibitors.