The combined use of CD34 and HLA-DR was more helpful in distinguishing Acute Promyelocytic Leukemia (APL) from non-Acute Promyelocytic Leukemia (non-APL) none of the eighteen cases of APL were positive for both CD34 and HLA-DR whereas 64.77% of non-APL (83%) were positive for both CD34 and HLA-DR. This evidence concerns the gene CD34 and acute promyelocytic leukemia.