RARA and acute promyelocytic leukemia: Hematopoietic differentiation and apoptosis in APL patients is blocked at the level of promyelocytes by the Promyelocytic Leukemia/Retinoic Acid Receptor alpha fusion protein caused by a t(15;17) chromosomal translocation (de Thé et al., 1990; Grignani et al., 2000).