Oncogenic, hotspot IDH1 and IDH2 mutations occur in 20% of AML cases and mechanistically it is well-established that these generate high levels of 2-hydroxy-glutarate (2HG) that aberrantly inhibit the activity of multiple epigenetic regulators leading to differentiation block and oncogenesis26,27. The gene discussed is IDH2; the disease is acute myeloid leukemia.