CD33 and acute myeloid leukemia: Immunophenotypic analysis of leukemic myeloid blasts in AML and MDS with excess of blasts (MDS-EB), exhibited a common pattern of leukemia associated immunophenotype (LAIP), which was characterized by CD117+ blasts with low side scatter and decreased or complete absence of CD13, CD34 and/or HLA-DR expression, increased CD33 and/or CD123 expression, as well as absence of CD15 and CD64 expression.