FLT3 and acute myeloid leukemia: FLT3-ITD (but not FLT3-TKD) mutations confer a poor prognosis in AML, especially when NPM1 is not co-mutated and the allelic FLT3-ITD/wild-type ratio is high; such mutations are usually conserved at relapse and have therefore emerged as a relevant therapeutic target [5,6].