IDH1 and anaplastic oligodendroglioma: Of the 45 samples, 22 (48.9%) of the patients with IDH mutation, including 7 patients with astrocytoma (WHO grade 2), 6 with anaplastic astrocytoma (WHO grade 3), 2 with anaplastic oligodendroglioma (WHO grade 3) and 7 with glioblastoma (WHO grade 4).