Additionally, patients were divided into four distinct categories according to the hormone receptor and HER2 status of their tumors, including ER+/PR+/HER2− (n = 157), ER+/PR+/HER2+ (n = 25), ER−/PR−/HER2+ (n = 11), and ER−/PR−/HER2−, or triple-negative breast cancer (TNBC; n = 37). Here, ESR1 is linked to triple-negative breast carcinoma.