Circulating WBCs and CFU-Cs in a cohort of control and VCAM-1–ablated mice, before and 8 weeks after splenectomy. (A) WBCs; (B) CFU-Cs. Mice were splenectomized at 9 to 14 weeks of age and tested 8 weeks after splenectomy (Spleen: –). Note significant increases in circulating CFU-Cs after splenectomy. Error bars indicate standard error of the mean (SEM).