ABCB1 and hepatocellular carcinoma: In addition, miR‐491‐3p, which can down‐regulate the expression of ABCB1 and its transcription factor Sp3 by directly targeting their 3′‐UTR, attenuated multidrug resistance of hepatocellular carcinoma.40 Furthermore, we found that XCT‐790 can increase the expression of miR‐9 and then trigger the decay of ABCB1 mRNA.