The results showed that the MPO+CD13homo+CD33homo+CD64dim and homo CD11c− or MPO+CD13homo+CD33homo+CD64dim and homoCD11c+CD117part∼+SSCinter-high CD10− panel efficiently identified APL with 100% sensitivity, specificity and accuracy among those non-APL patients with a CD34−HLA-DR−CD117+ immunopenotye. This evidence concerns the gene MPO and acute promyelocytic leukemia.