BAX and breast cancer: In addition, PCR results further revealed that miR-374a mimic decreased BAX expression, and increased BCL-2 expression on the mRNA level, while ISL reversed the anti-apoptotic effect of miR-374a in both MCF-7 and MDA-MB-231 cells (Fig. 4D), suggesting that miR-374a plays an essential role in the responses to ISL exposure in breast cancer cells.