Nevertheless, only IDH-wt gliomas, regardless of their histological grade (i.e. the presence of necrosis or microvascular proliferation) can be classified as molecular glioblastoma.15 The new World Health Organization classification rendered IDH-mutant Grade 4 histological gliomas as separate Grade 4 astrocytoma.15 This evidence concerns the gene IDH1 and astrocytoma (excluding glioblastoma).