CLL-1 expression on CD34⁺CD38⁻ stem cells in AML, normal bone marrow (NBM), regenerating bone marrow (RBM), and G-CSF–mobilized peripheral blood (MPB). After labeling of the cells with the appropriate antibody combinations, the CD34⁺CD38⁻ cells were identified by a precise gating strategy (as described in “Fluorescence-activated cell sorting analysis of CD34⁺CD38⁻”) and subsequently CLL-1 expression was determined. The percentage of CLL-1 expression on CD34⁺CD38⁻ cells for every individual patient and control is depicted with a symbol. In NBM, median CLL-1 expression was 0% (range, 0%-11%; n = 10); in RBM, 0% (range, 0%-5%; n = 6); and in mobilized peripheral blood (MPB), 0.6% (range, 0%-3.7%; n = 6). The CD34⁺ FAB M3 samples of this study showed CLL-1 expression on the CD34⁺CD38⁻ cells of 17%, 83%, and 89%.