FLT3 and acute lymphoblastic leukemia: In contrast, we found a high rate of FLT3 mutations in ETP-ALL compared to non-ETP T-ALL patients: 24 of the 25 FLT3 mutations were found in the ETP-ALL group, displaying a frequency of 35.3%, whereas non-ETP T-ALL showed a FLT3 mutations frequency of only 1.2% (P<.001).