Altered migration of fMIVIL-stimulated VSOP/Hv1 −/ − neutrophils. The clear migration defect in neutrophils lacking VSOP/Hv1 is revealed. Note the inability of VSOP/Hv1 −/ − neutrophils to detach their tail from the substrate. The images were acquired every 15 s during 45 min on an ImageXpress Micro automated fluorescence imaging system.