Flt-3

Flt-3 (FMS-like tyrosine kinase 3, CD135) is a class III receptor tyrosine kinase bearing five extracellular immunoglobulin-like domains. Binding of its ligand, Flt3 ligand, induces dimerization and activation that is essential for the proliferation and survival of hematopoietic stem and progenitor cells as well as dendritic cell development. In acute myeloid leukemia, FLT3 is among the most frequently mutated genes, with internal tandem duplications in the juxtamembrane domain or activating point mutations in the activation loop driving constitutive signaling and poor prognosis. These features established FLT3 as a validated target, and inhibitors such as midostaurin, gilteritinib, and quizartinib are used in AML therapy.