ESR1 and breast cancer: In this study, ER (10%) [9] and PR (20%) [16] status were included in 283 ER+/PR+/HER2− cases from January 2010 to October 2016 to explore the unique clinical features and the possible prognosis of HER2-negative breast cancer with different hormone receptor balance and to provide a theoretical basis for the treatment and research of patients with hormone receptor-positive breast cancer.