Calcium flux in cells from both NOD/SCID engrafting and nonengrafting AML cases. Samples were labeled with Indo-1 dye as described in “Calcium flux measurement.” The ratio of fluorescence due to dye bound to calcium over fluorescence due to unbound dye is displayed against time. Data were collected for 30 seconds, before addition of 100 ng/mL of SDF-1 and further analysis. All samples analyzed produced detectable intracellular calcium upon SDF-1 stimulation and no differences could be detected between NOD/SCID engrafting and nonengrafting AML cases.