Oligodendrogliomas are characterized by the presence of mutations in IDH1/2 alongside 1p/19q codeletion but almost never acquire alterations in TP53 or ATRX (signature of astrocytomas), as well as copy number amplification (signature of glioblastoma; Reuss et al., 2015). This evidence concerns the gene IDH1 and astrocytoma (excluding glioblastoma).