VCAM-1 cleaving activity in bone marrow extracellular fluid. Bone marrow extracellular fluid was harvested from wild-type mice (WT; lanes a-d and i-l), NE × CG-deficient mice (NE × CG; lanes e-h), or DPP-I–deficient mice (lanes m-p) after treatment with saline (–; lanes a, b, e, f, i, j, m, n) or G-CSF (+; lanes c, d, g, h, k, l, o, p). Cleavage of recombinant human VCAM-1 after incubation with bone marrow extracellular fluid was assessed as described in “Materials and methods.” Molecular size markers are indicated at left in kDa.