FLT3 and acute myeloid leukemia: Internal tandem duplication of the FLT3 gene is found in nearly 20% of AML and 5% of myelodysplastic syndrome cases.22 A previous study in Iran showed a frequency of 18% of FLT3/ITD mutations among Iranian AML patients, especially of the M3 subtype.37 Our results showed 16.0% of all 131 AML patients who participated in our study had FLT3/ITD mutations.