FLT3 and acute myeloid leukemia: In our cohort of 886 clinically and molecularly characterized AML patients, who were treated and followed at Seràgnoli Institute of Hematology-University of Bologna between 2002 and 2013, we found 5 CN-AML who were FLT3 ITD- at diagnosis and became FLT3 ITD+ at relapse or during follow-up.