Migration of neutrophils into the peritoneal cavity of WT and ICAM-2–deficient mice in response to different stimuli. WT and ICAM-2 KO mice were treated intraperitoneally with PBS (1 mL), IL-1β (10 ng/mL per cavity), TNF-α (100 ng/mL per cavity), or thioglycolate (4% solution in 1 mL per cavity). Four hours later, the peritoneal cavity was opened via a midline incision and the cavity lavaged with PBS (containing 0.25% BSA and 2 mM EDTA). Results represent the number of neutrophils that migrated into cavities. The data are presented as mean ± SEM of 3 to 7 animals. ***P < .001 versus responses obtained from saline-injected animals. In addition, significant differences between the 2 strains of mice are indicated by lines.