By analyzing first TM9SF4 expression in a small panel of AMLs pertaining from the M0 to M5 FAB subtypes, we found that TM9SF4 is overexpressed in some AMLs, particularly in acute myelomonocytic M4 AMLs and also in M2 and M3 AMLs, as compared to normal CD34+ HPCs, thus indicating that TM9SF4 expression is deregulated in AMLs with a granulocytic component and could play a role in the development of these leukemias. The gene discussed is CD34; the disease is leukemia.