Loss of ArhGAP15 causes increased in vitro and in vivo neutrophil migration. (A) Boyden chamber chemotaxis analysis of ArhGAP15^+/+ and ArhGAP15^−/− neutrophils; n = 5/genotype. (B) Representative fluorescence-activated cell sorter analysis of neutrophil CD88 and CXCR2 expression; n = 3/genotype. (C) Neutrophil recruitment to air pouches after saline (Co) or IL-8 injection; n = 6/genotype. (D-E) Peritoneal total cell recruitment and cellular subpopulation (MØ macrophages, NØ neutrophils, and LY lymphocytes) analysis after intraperitoneal administration of 1 × 10⁷ colony-forming unit of E. coli; n = 14/genotype. #P < .05. *P < .01. **P < .001.