Project description:Combined all trans retinoic acid (ATRA) / arsenic regimen cures virtually all acute promyelocytic leukemi (APL) patients. However, APL is often associated with activating FLT3-internal tandem duplication (ITD) mutation and the molecular bases for this effect remain unknown. Using mouse APL models, we demonstrate the FLT3-ITD severely blunts ATRA response.