WIF1 and breast cancer: To further confirm the direct binding between miR-552-5p and WIF1 3′-UTR, we compared the WIF1 expressions of MCF7, MDA-MB-231, MB453, and BT474 cells with MCF 10A cells, and the results revealed a significantly downregulated WIF1 expression in BC cells than in normal mammary gland epithelial cells (Figure 5B).