C3aR antagonist SB 290157 enhances total G-CSF–induced mobilization in wt mice. C3^–/– and C3aR^–/– mice, as well as age- and sex-matched wt mice, were mobilized for 3 or 6 days with G-CSF (250 μg/kg subcutaneously/day) (n = 21 animals/group). SB 290157 (500 μg/mouse) was injected intraperitoneally at day 3 or day 2, and at day 3 or days 1, 2, and 3 in suboptimal (A) 3-day mobilization protocols or at day 6 or day 5, and day 6 or days 4, 5, and 6 in optimal (B) 6-day mobilization protocols. Left panels: the number of MNCs/μL PB. Right panels: the number of circulating CFU-GMs/100 μL PB. * P < .000 01 compared with mice mobilized with G-CSF only. Data are expressed as mean ± standard deviation.