Indeed, consistent with the different expression of IGFBP2 in HSCs and leukemia cells, the signaling defects we observed in IGFBP2 deficient leukemia cells are more dramatic than in IGFBP2-null HSCs, and also are unique compared to defects observed in other cancer cells upon IGFBP2 deletion[23]. This evidence concerns the gene IGFBP2 and cancer.