(A) The effective dose of FX125L was determined after stimulation of 2 hours of human primary neutrophils and human uterine microvascular endothelial cells (hUtMVEC-Myo) with media conditioned by decidual cells isolated from term laboring patients (TL DCM, solid black bar, N=4) and TL DCM supplemented with increasing concentrations of FX125L (100–500nM, patterned grey bars). Neutrophils were loaded into the upper well of endothelial-coated inserts (200,000 cells/well, diameter of pore 3 μm), and allowed to transmigrate towards TL DCM ± FX125L for 1 hour. (B) To establish the inhibitory specificity of FX125L effect we pre-incubated for 2 hours primary neutrophils (NEU) and/or monolayers of uterine microvascular endothelial cells (hUtMVEC-Myo, ENDO) with TL DCM (solid black bar, N=4) ± FX125L (400nM, patterned grey bars). Neutrophils (200,000 cells/well) were loaded into the upper well of ENDO-coated inserts, and allowed to transmigrate towards media for 1 hour. Results are shown as number of primary neutrophils transmigrated through membrane inserts/well. All data was standardized to the negative control (serum free media). Pre-stimulation of neutrophils alone was as effective in inhibiting leukocyte migration as pre-stimulation of both neutrophils and endothelial cells, however the pre-stimulation of endothelial cells alone had no effect on the decrease of migration. Statistical significance was determined by one-way ANOVA. *p<0.05,**p<0.01 compared to TL DCM.