To determine if miR-191/425 cluster as a part of the ERα signaling can partially mediate the anti-proliferative effect that ERα showed in the aggressive breast cancer cells, a genome-wide expression analysis in aggressive MDA-MB-231 cells, which express low levels of miR-191/425, was performed 72 h after enforcing expression of both miR-191 and miR-425 and control oligonucleotide (Figure 4A). This evidence concerns the gene ESR1 and breast cancer.