Our previous study indicated that miR-190 did not alter the breast cancer proliferation [13], however, we observed that the expression of miR-190 was down-regulated in all ER- breast cancer cell lines (MDA-MB-453, MDA-MB-468, MDA-MB-231 and MDA-MB-435) as compared to ER+ breast cancer cell lines (MCF7 and T47D; Fig. 1a), suggesting that miR-190 may influence the breast cancer endocrine therapy sensitivity. This evidence concerns the gene ESR1 and breast cancer.