FLT3 and acute lymphoblastic leukemia: The frequency of both ITD and D835 mutations among adult ALL patients in this study was 0% (0/29); other studies have reported similar results;19,43,44 however, a few studies have reported FLT3 mutations among adult ALL patients at a very low frequency.18 As this is a rare occurrence, the limited sample size of this study is the most likely cause of the difference.