Basal L-selectin expression levels by neutrophils from ADAM17^ΔZn/ΔZn and control mice. Resting peripheral-blood leukocytes from the ADAM17^ΔZn/ΔZn- and ADAM17^+/+-chimeric mice, and wild-type C57BL /6 mice (WT) were double-stained for surface expression of L-selectin (left panel) or Mac-1 (right panel) and neutrophil marker Ly-6G. Relative staining levels were determined by flow cytometry. The dashed line indicates staining by an isotype-matched negative control mAb. The y-axis indicates cell number and the x-axis indicates log-10 fluorescence. Results are representative of 3 or more independent experiments.