AGO4 and hepatocellular carcinoma: Briefly, the observations include: (i) the mRNA expression of Dgcr8, p68/DDX5, p72, Dicer, Ago3, Ago4 and Piwil4 is significantly decreased in human primary HCC compared to the non-cancerous liver, and Dicer and p68 (mRNA) reduction in HCC is associated with poor prognosis [47].