RARA and acute promyelocytic leukemia: Acute promyelocytic leukemia (APL), classified as acute myeloid leukemia (AML) subtype M3 is characterized by a chromosomal translocation involving the retinoic acid receptor alpha (RARα or RARA) gene, which is distinct from other forms of AML in its responsiveness to all-trans retinoic acid (ATRA) therapy.