Mutations in isocitrate dehydrogenase 1 (IDH1) and 2 (IDH2) are common in multiple types of human cancer and cause accumulation of the oncometabolite D-2-hydroxyglutarate (D2HG) instead of α-ketoglutarate, driving cancers like gliomas and acute myeloid leukaemia by blocking cell differentiation and promoting tumour growth. The gene discussed is IDH2; the disease is glioma.