Amcenestrant (SAR439859) is a nonsteroidal, orally bioavailable, SERD studied in clinical trials (AMEERA) in postmenopausal women with HR+/HER2− advanced breast cancer [83] and in association with CDK4/6 inhibitors, such as palbociclib for previously untreated ER+/HER2− advanced breast cancer [84]. Here, ESR1 is linked to breast cancer.