ESR1 and breast neoplasm: Based on the optimal cut-off values of the ER Allred score (6), PR H-score (100), ER H-score (110), total ERα PIDs score (72.5), extranuclear ERα PIDs score (28), nuclear ERα PIDs score (48), and ERα ENR (0.5), 65 patients with HR+/HER2- breast tumors who received ET were classified into two subgroups.