PML and acute promyelocytic leukemia: Acute promyelocytic leukemia (APL) is caused by a reciprocal chromosomal translocation t(15;17) that fuses the genes encoding the promyelocytic leukemia (PML) protein and the retinoic acid receptor alpha (RARA) (de Thé et al., 1991; Kakizuka et al., 1991).