It needs to be pointed out that even though we followed the same definitions for HSC, CMP, GMP and MEP in AML samples as in healthy CB and PB using CD34, CD38, CD123 and CD45RA as antigens, these definitions of stem and progenitor compartments might not be valid in AML due to alterations in antigen expression. This evidence concerns the gene IL3RA and acute myeloid leukemia.