The expression of miR-21 was also significantly higher in HBV-associated HCC tumors than in HCV-associated or non-HBV/HCV HCC tumors (Supplemental Figure S5), suggesting that these microRNAs mediate maspin suppression and miR-21 is the most critical regulator in HBV-associated HCC tumors. The gene discussed is SERPINB5; the disease is hepatocellular carcinoma.