FLT3 and leukemia: Our results differ from human leukemia in that we observed the FLT3 ITD mutation not infrequently in ALL (2/7 samples), whereas in humans, the FLT3 ITD mutation is only rarely seen in ALL (~1% of ALLs) and is much more common in AML (25% of adult cases; 15% of pediatric cases) [1,2,13-15].