The unusual expression of CD7 and CD 64 with cytogenetic abnormality 46, XX, del(9q21:23.3) was observed in AML (M2)while in an ALL patient aberrant expression of CD10, CD13 and CD117 with cytogenetic abnormality 46, XX/46, XY was detected. This evidence concerns the gene ANPEP and acute myeloid leukemia.