MMP9 and hepatocellular carcinoma: To further investigate the molecular mechanisms of MUC1/JNK/TGF-β upregulated migration and invasion in HCC cells, the phosphorylation of Smad2L/C in TGF-β signaling pathway and the expression of its target gene MMP-9 were detected by Western blotting and/or qRT-PCR in both MUC1 gene silenced and overexpressing HCC cells.