In acute monoblastic leukemia, blasts may show a more immature immunophenotype, presenting a heterogeneous positivity of CD34, strong positivity of CD64 and HLA-DR, downregulation of maturating monocytic-associated markers CD36 and CD11b, and absence of mature monocytic-associated antigens CD14, CD35, and CD300c, together with downregulation of myelomonocytic markers cyMPO, CD13, CD123. This evidence concerns the gene CD34 and acute monocytic leukemia.