Dose-response analysis of AMD3100-induced mobilization of CD34⁺ cells into peripheral blood. Healthy human volunteers received a single subcutaneous injection of AMD3100 at the following doses: 40 μg/kg (n = 3; solid line); 80 μg/kg (n = 10; ○); 160 μg/kg (n = 5; ▴); and 240 μg/kg (n = 5; ▿). Peripheral venous blood was withdrawn at time intervals after drug administration, and FACS analysis was used to determine the concentration of CD34⁺ cells. Each value represents the mean ± SEM.