FLT3 and acute myeloid leukemia: It can either affect the juxtamembrane domain and the activation loop of the tyrosine kinase domain (TKD) (~7% of AML cases), resulting in the constitutive activation of FLT3, or it can be an internal tandem duplication (ITD), leading to a disrupted juxtamembrane domain that has been shown to be crucial for kinase autoinhibition (~23% of AML cases) [6].