On a background of their efficacy in AML [59,60], phase 1 trials studying the mutant IDH1 inhibitor, ivosidenib, and the mutant IDH2 inhibitor, enasidenib, are both underway in patients with CCUS to determine their impact on hematologic parameters in this population (NCT05030441; NCT05102370). The gene discussed is IDH2; the disease is acute myeloid leukemia.