These data from primary IDH1- and IDH2-mutant AML specimens are in agreement with a negative impact of high 2HG levels on OXPHOS capacity38, the effect of IDH1 and IDH2 mutations on the TCA cycle and OXPHOS in AML39,40, the coupling of the TCA cycle to OXPHOS3, and the suppressed OCR and reduced TCA cycle activity associated with IDH1 mutations in glioma41,42. Here, IDH2 is linked to acute myeloid leukemia.