JMJD4 and hepatocellular carcinoma: The patients with high RIG-I and low JMJD4 in HCC had significant worse outcome than that of the high RIG-I and high JMJD4 group (Fig. 7e, Additional file 2: Fig. S7c), suggesting that RIG-I and JMJD4 co-operatively predict better prognosis, and JMJD4-mediated RIG-I demethylation may be important in the identification of HCC prognosis.