Emerging evidence suggests that miRNAs regulate normal liver development and metabolism whereas miRNA dysregulation is associated with a variety of liver disorders, including HCC.4, 5, 6, 7, 8, 9 The universal function of miRNAs in normal liver physiology was addressed in a mouse model lacking Dicer function in hepatocytes as Dicer is an essential enzyme for miRNA processing. The gene discussed is DICER1; the disease is hepatocellular carcinoma.