The safety and efficacy of Enasidenib demonstrated in a phase 1/2 trial in IDH2-mutant advanced myeloid malignancies (including AML and MDS) paved the way for FDA approval of the first small molecule mutIDH inhibitor in cancer and propelled global clinical research efforts for IDH-based targeted cancer treatments (ClinicalTrials.gov NCT01915498) (12). The gene discussed is IDH2; the disease is acute myeloid leukemia.