E2F1 and hepatocellular carcinoma: In addition to E2f1, we found that Pontin, Reptin and H2a.z also display higher expression in TKO HCC compared with control livers (Fig. 6c–e, see Supplementary Fig. 9a for the uncropped autoradiograms and the Ponceau staining of Fig. 6c; an average of 11.44-fold for H2a.z compared with controls, 3.39-fold for Pontin and 4.02-fold for Reptin) and our data identified H2a.z as a new E2f target gene (Fig. 6f,g).