FLT3 and leukemia: To study changes of the vascular compartment of the BM niche during leukemia growth, we then utilized the MllPTD/WT/Flt3ITD/ITD mouse, a model that recapitulates phenotypic, cytogenetic, molecular and pathological features of human FLT3-ITD+ AML, a relatively frequent molecular subset of the disease [11].