FLT3 and acute promyelocytic leukemia: Similarly, the prognosis value of FLT3-ITD or FLT3 mutations, present in about half of APL cases, remains unknown in the context of ATRA and/or ATO-based therapies, which may be correlated with a WBC higher than 10 × 109/L, which is a well-established poor risk prognosis factor [20,34,73,80,81,82].