In addition, a chromosome 1p/19q co-deletion is shown in 50–80% of oligodendrogliomas, while 1p/19q deletion is not observed in liponeurocytomas and also oligodendrogliomas show a high frequency of isocitrate dehydrogenase 1 (IDH1 R132H) mutation in addition to 1p/19q co-deletion [16]. This evidence concerns the gene IDH1 and oligodendroglioma.