Four groups of mice (5 each) were treated with either G-CSF (200 μg/kg/d or KL (100 μg/kg/d) for 3 days or with combinations of G-CSF plus anti-VLA4 or KL plus anti-VLA4 again for 3 days; anti-VLA4 was given intravenously at 1 mg/kg/d). The combination treatments led to significant enhancement of mobilization of both CFU-C and CFU-S12 compared with cytokine-only–treated controls or anti-VLA4 alone–treated controls (anti-VLA4 alone gives 200 to 900 CFU-C/mL depending on the strain of mice, see also Fig 4).