Similarly, compared to control human hepatoma HepG2 cells, SMAD4 transcript expression was significantly reduced by ∼40% (p<0.05) in cells where miR-224 precursor was introduced and significantly increased by ∼60% (p<0.001) in cells where miR-224 inhibitor was introduced (Fig. S4 in File S1). This evidence concerns the gene SMAD4 and hepatocellular carcinoma.