CD33 and myelodysplastic syndrome: Analysis of the immunophenotype of IDH1/2-mutated AML/MDS-EB cases showed a highly significant association between the simultaneous presence of IDH1/2 and NPM1 mutations and confirmed the double negative ‘acute promyelocytic leukemia-like’ myeloid phenotype described above: lacking both, CD34 and HLA-DR and highly expressing MPO and CD33 (175).