E2F1 and hepatocellular carcinoma: Using UCSC Xena, we first analyzed four above-described potentially important upstream regulators, FOXM1, MYBL2, E2F1 and PPARGC1A. We found that FOXM1, MYBL2 and E2F1 were all significantly upregulated while PPARGC1A was significantly downregulated in HCC, fully consistent with the results observed in HCN-NOS (Supporting Figure 6A).