The numbers of marrow derived myeloid progenitors, specifically (granulocyte, macrophage [CFU-GM], erythroid [BFU-E], and granulocyte, erythroid, megakaryocyte, macrophage [CFU-GEMM]), in the bone marrow of untreated and AMD3100-treated C57BL/6 control mice and CD26-/- mice. Comparisons of untreated groups to AMD3100-treated groups were done using a two-tailed student t-test assuming equal variance, n=7-10 mice per group.