Acute promyelocytic leukemia (APL) is a well-defined type of acute myeloid leukemia (AML), characterized by the balanced t(15,17) chromosomal translocation, resulting in the fusion of the promyelocytic leukemia (PML) and retinoic acid receptor-α (RARA) genes. The gene discussed is PML; the disease is acute promyelocytic leukemia.