PML and acute promyelocytic leukemia: APL is characterized by a reciprocal translocation between chromosomes 15 and 17, t(15;17), expressing the fusion of promyelocytic leukemia (PML) gene to the retinoic acid receptor α (RARα) gene resulting in the production of a PML-RARα fusion protein [12], this fusion protein may block the differentiation of hematopoietic progenitor cells [13–14].