SMAD4 and hepatitis B virus infection: To identify the pathways involved, we mapped the KEGG database and found that the top 20 significantly dysregulated miRNAs were enriched in 30 pathways (Figure 4), that included enrichment of miRNA-predicted targets of hepatitis B (i.e., NFKB1, CDK4, E2F3, KRAS, MYC, KRAS, BCL2, CDKN1A, APAF1, MYD88, SMAD4, and others), hepatitis C (GSK3B, STAT3, NFKB1, PME3, EGFR, and others), viral carcinogenesis, as well as various cancers and signaling pathways related to cancer development.