As displayed in Supplementary Fig. S2, five transcription factors (CREB1, CTCF, YY1, E2F1, MYBL2) were significantly elevated with tumor progression in HCC, indicating that these potential transcription factors may be responsible for the upregulation of H3–H4 histone chaperones in HCC. Here, CREB1 is linked to hepatocellular carcinoma.