Transmigration routes in CCL3-, CXCL1-, and PAF-elicited leukocyte responses. (A) Representative in vivo microscopy image of a postcapillary venule in the inflamed cremaster muscle, immunostained for PECAM-1 (scale bars: 20 μm). Arrow indicates a firmly adherent leukocyte colocalizing with PECAM-1–immunoreactive endothelial junctions (green). (B) Results for the relative localization of firmly adherent leukocytes to PECAM-1–immunoreactive endothelial junctions in postcapillary venules of WT mice undergoing stimulation with CCL3, CXCL1, or PAF (mean ± SEM for n = 3 per group).