WT1 and hepatocellular carcinoma: Downregulation of WT1-AS expression by shRNA in L02 cells did not affect WT1 transcription, whereas overexpression of WT1-AS in HepG2 cells significantly down-regulated the level of WT1 mRNA, suggesting that WT1-AS might downregulate WT1 expression in HCC through a direct interaction rather than by blocking transcription.