Disruption of CXCL12/CXCR4 signaling is a common feature in cytokine-induced mobilization. Wild-type mice (n = 6-8 each group) were left untreated (ctrl) or treated with G-CSF, Flt3L, or SCF for 7 days. Shown is the number of CFU-Cs in the blood (A) and bone marrow (B). (C) CXCR4 surface expression of Kit⁺ lineage⁻ cells in the blood (PB) and bone marrow (BM) was measured by flow cytometry. Shown is the mean fluorescent intensity (MFI). (D) The migration of CFU-Cs isolated from the blood or bone marrow in response to CXCL12 was measured using a transwell assay. Shown is the percentage of input CFU-Cs that migrated in response to CXCL12. (E) CXCL12 mRNA expression in the bone marrow (relative to β-actin) was measured by real-time RT-PCR. (F) CXCL12 protein expression in bone marrow plasma was measured by ELISA. Shown is the expression relative to control bone marrow. Data represent mean ± SEM; *P < .05; **P < .01.