Given the complexity of molecular environment of different breast cancer cell lines, we took SK-BR-3 (a breast cancer cell line that is sensitive to growth inhibition induced by depletion of ERRα) and MDA-MB-231 (a breast cancer cell line with high migratory capacity) as cell models respectively to further elucidate the mechanism underlying the inhibitory effect of miR-137 on the proliferation and migration of breast cancer cells. This evidence concerns the gene ESRRA and breast cancer.