RIGI and hepatocellular carcinoma: Chemical carcinogen DEN-induced hepatocarcinogenesis goes through premalignant liver cancer progenitor HcPCs to fully established HCC, and we first examined RIG-I expression during hepatocarcinogenesis, including normal hepatocytes, nonaggregated hepatocytes and aggregates containing HcPCs from mice five months post-DEN injection [4, 25], and established HCC cells eight months post-DEN injection.