Integrating the genetic findings of these high grade gliomas with IDH mutations and 1p/19q co-deletions, as suggested by a recent international consensus of neuropathologists, would lead to their categorization as anaplastic oligodendroglioma, WHO grade III, with IDH mutation and 1p/19q co-deletion, rather than GBM-O [43]. This evidence concerns the gene IDH1 and glioma.