Hepatoma cells (SK-Hep1 and Huh 7) transfected with ISX shRNAi showed significant downregulation of E2F1 and DP1 protein expression as well as of proliferation markers (cyclin D1, c-Myc, Cdc25A, and PCNA) and anti-apoptotic genes (p65 and Mcl-1) (Figures 3F and S1C). This evidence concerns the gene PCNA and hepatocellular carcinoma.