Therefore, a combination of cMPO, CD34, HLADR, CD117, CD33, CD15, CD11c, CD64, CD9, and CD18 can diagnose APL with high specificity and sensitivity by excluding other hypergranular AML as few cases of NPM1-positive AML mimicking APL on morphology and also in cases showing CD34 and HLA-DR negativity on flow cytometry, that can pose a diagnostic dilemma. This evidence concerns the gene NPM1 and acute myeloid leukemia.