On the other hand, a significant down regulation of DDX3 expression is found in hepatocellular carcinoma (HCCs) from the hepatitis B virus (HBV) positive patients20, In the hepatocellular carcinoma model, DDX3 found to act as a tumor suppressor by activating the expression of cyclin dependent kinase inhibitor p21cip121. This evidence concerns the gene DDX3X and neoplasm.