CD34 and acute promyelocytic leukemia: This work focuses on “APL-like” NPM1m AML, also known in the literature as “double-negative” (DN) NPM1m AML (CD34− HLA-DR−), whose immunophenotype indeed resembles differentiated granulocytic precursors, making it difficult to distinguish from APL, which is, by definition, CD34− HLA-DR−.