Increased HPC mobilization in αM^–/– mice treated with CY and G-CSF. (A) G-CSF mobilization. αM^+/+ (□) and α^–/– (▪) mice were treated with G-CSF (250 μg/kg/d) over a period of 1 (n = 8), 2 (n = 8-10), or 4 (n = 5) days. Three hours after the final injection, nucleated cells were isolated from blood and plated to assay CFU-Cs. *P = .02 compared with αM^+/+. (B) CY mobilization. αM^+/+ (□) and αM^–/– (▪) mice were given a single intraperitoneal dose of CY (100 or 200 mg/kg). Nucleated cells from peripheral blood were harvested after 8 days and assayed for CFU-C content. Shown are mean ±SEM numbers of CFU-Cs per milliliter of blood. **P = .01 compared with αM^+/+ mice.