Multiple IDH1 and IDH2 inhibitors are reported, though only one IDH1 inhibitor (ivosidenib) and one IDH2 inhibitor (enasidenib) have been approved for clinical use, i.e. for acute myeloid leukaemia (AML) treatment where the cancer cells make an IDH variant12,13. The gene discussed is IDH2; the disease is acute myeloid leukemia.