Based on transfection efficiencies and cell viabilities after nucleofection, we chose three individual cell lines, K562 and OCI-AML3 with the lowest and the highest basal wild-type FLT3 expression respectively, and Jurkat cells with undetectable FLT3 expression as negative control14, to generate isogenic leukemia clones using our designed TALENs. This evidence concerns the gene FLT3 and leukemia.