ESR1 and neoplasm: For example, miR-22 was found to inhibit breast cancer progression by directly targeting ESR1 (12); miR-873 enhanced tamoxifen sensitivity via indirect suppression of transcriptional activity of ERα by targeting CDK3 which is key for phosphorylating ERα (13); miR-142-3p acted as a tumor suppressor in ER-positive breast cancer by targeting ESR1 (14).