ROS are required for direction migration. Neutrophil directional migration toward fMLP was determined using a Zigmond chamber. XY-plots represent the end points of migrating neutrophils in respect to the origin. (A) The majority of wild-type neutrophils migrate toward fMLP. (B) Neutrophils incubated with NAC (10mM) migrated in a random fashion. (C) Neutrophils lacking the NOX2 subunit Gp91 (defect in ROS production) also did not show directionality toward fMLP. (D) The average percentage of neutrophils migrating toward fMLP was calculated from 3 independent experiments ± SD. Neutrophils derived from C57/BL6 were used as control for gp91null cells. (E-H) Directionality of WT neutrophils toward fMLP was determined in the presence of (E) Trolox (100μM), (F) VO-OHpic (75nM) or (G) Trolox + VO-OHpic. VO-OHpic could rescue Trolox-mediated inhibition of directionality. The XY-plots represent the end points of migrating neutrophils in respect to the origin. (H) The average percentage of neutrophils migrating toward fMLP was calculated from 3 independent experiments ± SD.