Association of PML-RARα LBD mutations (PRα/LBD⁺), FLT3 mutations and additional chromosome abnormalities (ACAs) in relapsed acute promyelocytic leukemia (APL) on all-trans retinoic acid (ATRA)/chemotherapy (CT). TTR indicates time to relapse. The bottom panel represents the more recently developed ATRA/arsenic trioxide (ATO) combination therapy for the newly diagnosed APL, which can eradicate the leukemia clone through induction of PML-RARα degradation and lead to a long-term clinical remission in the overwhelming majority of patients.