SMAD2 and hepatocellular carcinoma: Recently, several kinds of microRNAs (miRNA) have been reported to regulate Smad/EMT signaling; in contrast, miRNA-125b and miRNA-708 suppress Smad2 and Smad3 pathway and attenuate EMT [139,140], miRNA-520g down-regulates Smad7 and promotes EMT in HCC cells [141].