RIGI and hepatocellular carcinoma: Loss of IL-6 diminished DEN-induced HCC, and importantly, Rig-Ihep−/−IL-6−/− mice and IL-6−/− mice displayed a similar reduced induction of HCC by DEN (Fig. 2b), suggesting that hepatic RIG-I deficiency failed to promote hepatocarcinogenesis under IL-6 deficiency.