At the molecular level, as a result of the t(15;17) translocation, the gene for retinoic acid receptor alpha (RARA) on 17q21 fuses with a transcription factor gene (promyelocytic leukemia or PML) on 15q22, giving rise to a PML/RARA gene fusion product [2]. This evidence concerns the gene RARA and acute promyelocytic leukemia.