IDH2 and central nervous system cancer: To further explore the prognostic impact of IDH1 mutation, we subdivided both grade II and III gliomas patients in three prognostic subgroups, based on the 1p19q codeletion and IDH1 mutation status ((i) IDH mut/1p19qdel, (ii) IDH mut/1p19qnon del, (iii) IDH non mut/1p19qnon del).