In vivo G-CSF therapy increases PMN numbers in BM of sB1^−/− mice. (A) BM PMN, (B) myelocyte, and (C) blood PMN numbers were determined 24 hours after recombinant murine G-CSF therapy for 5 consecutive days. Cell numbers of individual WT (●) and sB1^−/− female mice (○), respectively. Untreated females (Figure 2 subset) were similar to saline control females and were compared with the G-CSF–treated mice. Statistical analysis was performed using 2-way ANOVA with Bonferroni posttest. (**P < .01; ***P < .001).