Isocitrate dehydrogenase (IDH) mutation is frequently found in WHO grade II–III oligodendrogliomas and astrocytomas [8, 9], and is currently implicated as a prerequisite of tumorigenesis for some types of diffuse gliomas and a precondition of 1p/19q co-deletion [10, 11]. Here, IDH1 is linked to oligodendroglioma.