AML-cell adhesion to fibronectin and BMEC is decreased after elastase inhibition. AML cell lines (U937, HL-60, and ML-1) either untreated or treated for 30 minutes with EI (10 μg/mL) were placed on fibronectin (FN; ▪) or BMEC-coated (□) plates with SDF-1 (100 ng/mL) for 2 hours, and adhesion was measured as described in “Materials and methods.” Results are mean ± SE of 3 to 5 independent experiments; ^*P ≤ .05; ^**P ≤ .001.