Overview Introduction Leukocytes play an important role in eliminating offending agents login to view 1 more bullet The process of leukocytes migrating from the blood vessel to tissue involves multiple steps and are mediated by adhesion molecules and chemokines login to view 15 more bullets StepMolecule on Vasculature/StromaMolecule on Leukocyte1. Loose adhesion, rolling E-selection, P-selectinSialyl Lewis2. Tight adhesion ICAM-1LFA-1 (integrin)3. Diapedesis PECAM-1PECAM-14. Migration through ECMBacterial products, C5a, IL-8, LTB4, KallikreinVarious