Cell cycle analysis. C57BL/6 mice were treated with the CXCR4 antagonists POL5551 (100 mg/kg per day for 1 or 2 weeks), AMD3100 (20 mg/kg per day for 2 weeks), and ALT1188 (33 mg/kg per day for 2 weeks) via subcutaneous infusion. Control groups received G-CSF (100 μg/kg per dose, 4 or 9 doses every 12 hours) or PBS (controls). (A) Representative Ki67 and 7-aminoactinomycin (7-AAD) staining plots gated on LSK (upper panel) or LSK SLAM (lower panel) cells in the BM of differentially treated mice. Distribution of BM (B) LSK and (C) LSK SLAM cells in G₀/G₁/G_2/S/M phases of the cell cycle (data represent the mean ± SEM of 7 mice per cohort). ***P < .001; **P < .01; *P < .05.