IDH1 p.Arg132His is the predominant IDH pathogenic variant in glioma (90%) and IDH2 p.Arg140Trp is one of the hotspot variants commonly seen in acute myeloid leukemia and only rarely observed in gliomas (Andersson et al. 2011; Meggendorfer et al. 2018). Here, IDH2 is linked to central nervous system cancer.