To explore a histone demethylase with oncogenic characteristics for HCC, We first analyzed expression profiles of a number of histone demethylase genes in a subset of HCC samples by using public GEO Profiles database (GSE 25097) and found that KDM5B was the most obvious up-regulated histone demethylase with at least 2-fold up-regulation in 40 % HCC specimens (Fig. 1a). This evidence concerns the gene KDM5B and hepatocellular carcinoma.