Approximately 30% of cases of acute myeloid leukemia (AML) aberrantly express a mutated Fms-like tyrosine kinase 3 (FLT3) gene characterized by an internal tandem duplication (ITD), point mutations within the juxtamembrane (JM) domain, or point mutations in the tyrosine kinase domain (TKD)1. The gene discussed is FLT3; the disease is acute myeloid leukemia.