ABCB1 and cancer: The expression levels of MDR1 mRNA and P-glycoprotein (P-GP) and homeodomain-interacting protein kinase-2 (HIPK2) proteins are upregulated after upregulating the miR-27a level in cancer cells, while the sensitivity to paclitaxel is decreased in cancer cells transfected with miR-27a mimics (8, 92).