Comparison of eosinophil recruitment and EPO levels in P-selectin–deficient and wild-type mice. Ragweed-sensitized mice (P-selectin–deficient or control wild-type mice; n = 9 mice; 3 separate experiments) were challenged with an intraperitoneal injection of ragweed allergen. Forty-eight hours later, the percentage of transmigrated peritoneal eosinophils (A) and EPO levels (B) were assessed. P-selectin–deficient mice developed significantly less peritoneal eosinophilia (P = .005) and lower EPO levels (P = .05) compared with control wild-type mice after allergen.