Neutrophils are rapidly recruited to the peritoneum following IL-33 administration. (A) Percent neutrophils in peritoneal lavage of mice treated for 6 hours with 0, 0.1, 1, 10, 100, or 1000 ng IL-33. (B) Neutrophil infiltration over time in mice injected with 100 ng IL-33. Values are presented as mean ± SEM (n = 4-5) *P < .05. ns = not significant.