The cases were reclassified as follows: 42 (23 males and 19 females; average age 45.26 ± 12.01) cases of astrocytoma carrying mutant IDH where 17, 11, and 14 cases were grades 2, 3, and 4, respectively; 16 (12 males and four females; average age 46.19 ± 12.12) cases of oligodendroglioma carrying mutant IDH with 1p/19q-codeleted, where 8 cases each were grades 2 and 3; and 57 (31 males and 26 females; average age 54.75 ± 13.08) cases of GBM, IDH-wildtype. This evidence concerns the gene IDH2 and oligodendroglioma.