The initial oncogenesis of IDH-mutant gliomas arises from aberrant oncogene expression in a setting of epigenetic dysregulation resulting from the inhibitory activity of D-2-hydroxyglutarate (D-2HG) levels, the oncometabolite produced by mutant IDH, on DNA and histone demethylases [2,3,4]. Here, IDH2 is linked to central nervous system cancer.