EREG and breast cancer: Endocrine therapy (tamoxifen), upregulates EREG in BC cells by downregulating miR-186-3p, and miR-186-3p inhibits EGFR signaling via targeting EREG in tamoxifen-resistant inT47D-TR cells, indicating that miR-186-3p is a promising therapeutic target in tamoxifen-resistant BC (He et al. 2019).