Neutrophil counts in mice treated with G-CSF. Mice were injected subcutaneously with G-CSF (250 μg/kg/d) for 7 days. Blood was collected daily and analyzed as described in Materials and Methods. Data are from 7 to 11 animals for each genotype. Error bars represent standard error of mean. gcsfr-wt/wt, (□);gcsfr-wt/▵715, (▧); gcsfr-▵715/▵715, (▪).