A subtype of Acyte Myelogenous Leukemia, Acute promyelocytic leukemia (APL) is due to a chromosomal translocation (chromosomes 15 and 17), involving the retinoic acid receptor alpha (RARA).

Acute Promyelocytic Leukemia is due to a chromosomal translocation between chromosomes 15 and 17.

Translocation results in the fusion between the retinoic acid receptor alpha (RARA) on chromosome 17, and the promyelocytic leukemia (PML) genes.

The fusion gene gives rise to a hybrid protein that blocks the transcription and differentiation of promyelocytes and granulocytes.

Acute Promyelocytic Leukemia is the only leukemia that can be treated with all-trans retinoic acid (ATRA)