C19orf48P and acute promyelocytic leukemia: A possible explanation of such high sensitivity of APL to anthracycline drugs maybe the low expression of the multidrug-resistance related protein (MDR-1) on the membrane of leukemic cells.30–33 Therefore, because ATRA therapy alone induced short-lived remissions, anthracycline-based regimens associated to ATRA have been administered to patients with APL.