G-CSF targets expression of B-trophic factors in CAR cells and osteoblasts. (A) Cxcl12^gfp mice were treated for 7 days with G-CSF or PBS, and CAR cells in the bone marrow were quantified by flow cytometry. (B) Representative photomicrographs showing the relationship of CAR cells to B220⁺ (cyan) immunoglobulin M (IgM^–) (red) B-cell precursors. Scale bar = 50 μm. (C) Quantification of the number of B220⁺IgM^– cells within 1 µm of a CAR cell (n = 7-11). (D) Expression of CXCL12 mRNA relative to β-actin mRNA in sorted CAR cells (n = 4-5). (E) RNA expression profiling of sorted CAR cells was performed. Shown are probe signals for the indicated genes (n = 4-5). (F) Col2.3-Gfp mice were treated for 5 days with G-CSF or PBS, and the number of Col2.3-GFP⁺lineage^–CD45^– osteolineage cells was quantified by flow cytometry (n = 7). (G) The expression of the indicated genes relative to β-actin in sorted osteoblasts is shown (n = 7). Statistics by two-tailed Student t test, *P < .05; **P < .01; ***P < .001; or statistical analysis of microarrays, ⁺FDR < 0.05; ⁺⁺⁺FDR < 0.001. FDR, false discovery rate.