ESR1 and breast carcinoma: Breast cancer (BC) remains a significantglobal health challengeand a leading cause of morbidity among women.1 Triple-negative breast cancer (TNBC) is a highly aggressive BC subtype,characterized by the absence of estrogen receptor (ER), progesteronereceptor (PR), and human epidermal growth factor receptor 2 (HER2)expression.2 As a specific subtype of BC,TNBC exhibits aggressive clinical behavior, with approximately 45%of patients experiencing distant metastases and significantly reducedsurvival.