IDH1 and oligodendroglial tumor: The mean methylation scores of IDH-wild-type astrocytic tumors (mean methylation score: 0.53, p = not significant) and of IDH-mutant and 1p/19q-codeleted oligodendroglial tumors (mean methylation score: 0.85, p = not significant) were not significantly different from non-neoplastic brain tissue (mean methylation score: 0.3).