There appears to be three distinct types of GII/III s, those with and IDH1 mutation and 1p and/or 19 q deletions (mostly oligodendrogliomas) [33], those with and IDH1 mutation but no 1p/19q cytogenetic changes (further subdivided into whether they have ATRX or CIC and FUBP1 mutations [34]) and IDH1 wild-type GII/III s, which tend to have EGFR amplification and have been described as “pre-GBM” [34]. Here, IDH1 is linked to oligodendroglioma.