Increases of HCA incidences (males, 20%; females, 20%; p = 0.05) and multiplicities (males: 0.3 ± 0.6/mouse, p = 0.05; females, 0.2 ± 0.4) were detected in livers of the DMBDD-initiated Ogg1−/− mice as compared to the Ogg1−/− controls (males, 0%, 0.1 ± 0.2/mouse; females, 0%, 0/mouse) and DMBDD-treated Ogg1+/+ groups (males, 5%, 0.1 ± 0.2/mouse; females, 0%, 0/mouse). This evidence concerns the gene OGG1 and hepatocellular adenoma.