DNMT3B and benign neoplasm: While DNMT3b protein was detected in 64 (58.2%) of the 110 serous cancer cases and 22 (71.0%) of the 31 serous benign tumors, indicating that DNMT3b expression in ovarian cancers was lower but not significantly than that of benign tumors (Mann-Whitney U-test test, P = 0.054; Table 2), but the difference was not observed in mucious tumors (Mann-Whitney U-test test, P = 0.536; Table 2).