Flt3 in acute myelogenous leukemia: biology, prognosis, and therapeutic implications.

Flt3 is a tyrosine kinase receptor expressed on hematopoietic cells. Activating mutations of this receptor are encountered in over one-fourth of acute myelogenous leukemia (AML) cases and activate multiple intracellular pathways leading to cell proliferation, inhibition of apoptosis, and blockage of differentiation in leukemic blasts. AML with flt3 mutations has a worse prognosis than AML with normal flt3, at least in younger patients. Several flt3 inhibitors are in various stages of preclinical and clinical development and it is hoped that specific therapies against AML with flt3 mutations will soon be available to the clinician.