SOX9 and breast cancer: In accordance with the effects observed in MDA-MB-231 cells, we confirmed decreased luminescence signal intensity in MCF-7 and in HEK293 cells to be caused by miR-134-3p and miR-224-3p (Fig. 2B, C), suggesting direct SOX9 targeting by these miRNAs across various breast cancer cell lines and HEK293 cells.