Leukemia stem cell mobilization in the MN1 leukemia model. (A) Number of transduced white blood cells in peripheral blood of control or drug treated mice. Eighteen or 19 days after transplantation of MN1-transduced bone marrow cells to lethally irradiated mice, solvent (CTL), G-CSF, AMD3100, or MOL27575 were injected subcutaneously for 3 consecutive days. Peripheral blood was harvested and pooled from 4 to 5 mice per group, and white blood cells were counted and immunophenotyped for the proportion of GFP⁺ (leukemic) cells (95% confidence intervals do not overlap between CTL and AMD3100 indicating a significant difference). (B) Results of CRU assays to determine the leukemia stem cell frequency in peripheral blood and bone marrow of G-CSF, AMD3100, or MOL27575 treated mice. Peripheral blood or bone marrow from 4 to 5 mice per treatment group were pooled and transplanted by limiting-dilution analysis (5 cell doses of GFP⁺ cells, 3 mice per cell dose). LSC frequency was calculated from the proportion of leukemic mice by Poisson statistics. Overlapping 95% confidence intervals indicate no statistically significant difference. *LSC frequency in bone marrow of a historical control group is shown for comparison.