The role of E2Fs in digestive malignancies is often dictated by the status of vital cell cycle regulators, such as pRb, p16INK4A, with many E2Fs-involved intricate loops.35, 36 Thus, the above results revealed that ANCCA/PRO2000-miR-520a-E2F2 regulatory loop cooperatively promoted cell proliferation in HCC cells. This evidence concerns the gene RB1 and hepatocellular carcinoma.