IDH2 and acute myeloid leukemia: The neomorphic mIDH2 enzyme is a promising drug target, and after much pre-clinical work59,60, the first-in-human phase I/II study of an IDH2 inhibitor (enasidenib), conducted by Steinet al. (including our center), showed an overall response rate (ORR) of 40.3% and a CR rate of about 20% (24.4% for IDH2-R172 and 17.7% for IDH2-R140 isoforms) in relapsed/refractory AML patients (176 patients, many heavily pre-treated)61.