IDH1 and oligodendroglioma: In order to determine whether AVIL protein expression levels correlate with tumor grade and/or IDH mutation status, we performed a semiquantitative analysis of AVIL IHC data on a set of diffuse gliomas, consisting of grade II astrocytomas and oligodendrogliomas (n = 11, grade III astrocytomas and oligodendrogliomas (n = 14) and grade IV glioblastomas (n = 15) (Supplementary Fig. 3i).