Noteworthy, the 1p/19q codel only occurs in patients harboring mutation in either IDH1 or IDH2 (herein named as IDHm) [8], ultimately subgrouping glioma patients into three molecularly distinct groups: 1) tumors harboring IDHm with 1p/19q codel (Oligodendroglioma), 2) tumors with IDHm and intact 1p/19q (Astrocytoma), and 3) tumors with IDH wild-type (Glioblastoma) [3, 4]. The gene discussed is IDH1; the disease is oligodendroglioma.