ESR1 and breast cancer: Other novel endocrine therapies including SERMs (e.g., lasofoxifene) [79], PROTACs (e.g., ARV-471) [86], SERCAs (e.g., H3B-6545) [87], and CERANs (e.g., OP-1250) have emerged for the treatment of ER+ breast cancer Table 3.