Overexpression of miR-20b-5p promotes the malignant behavior of breast cancer stem cells by bidirectional regulation of CCND1 and E2F1 (27); while the deletion of miR-20b and miR-17 enhances the resistance of breast cancer to taxol by inhibiting the expression of NCOA3 (28). This evidence concerns the gene E2F1 and breast carcinoma.