ABCB1 and hepatocellular carcinoma: More surprisingly, we unexpectedly found the induction of multidrug resistance gene MDR1, p‐glycoprotein, is strongly associated with the imbalance of Smad3/Smad7 signalling in both the primary and recurrent HCC (Figure S1), implying a potential role of Smad signalling in the development of HCC multidrug resistance.