FLT3 and leukemia: Comparison of inhibition of cellular proliferation after quizartinib treatment revealed strong correlation between naturally occurring and engineered cell lines expressing identical mutant kinases (Figure 3A): Ba/F3 cells stably transfected with a vector encoding for a FLT3 ITD were equally highly sensitive to quizartinib compared to the human FLT3 ITD positive leukemia cell line MOLM14.