IGFBP2 and acute myeloid leukemia: In drastic contrast to the observation that normal HSCs do not show a detectable IGFBP2 mRNA level and differentiated hematopoietic cells express significant amount of IGFBP2[19], IGFBP2 is highly expressed in both AML stem cells (AML-SC) enriched bone marrow Lin-Kit+Sca-1- cells[38] and differentiated Lin-Kit-Sca-1- cells in the AML1-ETO9a AML model (Figure 3A).