The emerging nature of DS as an adverse reaction in non-APL AML, and some differences in clinical presentation have led to missed cases with the IDH inhibitors ivosidenib and enasidenib, and an FDA Drug Safety Communication was released in November 2018 for enasidenib following fatal cases in the postmarketing setting [21,22]. The gene discussed is IDH1; the disease is acute myeloid leukemia.