Lsc is required for normal migration of formyl-peptide–stimulated neutrophils. DIC photomicrographs (25 × objective) of WT and Lsc KO neutrophils stimulated with 10 μM fMLP in a Zigmond chamber were obtained at 15-second intervals for 15 minutes as described in Figure 3A and subjected to quantitative analyses of cell migration (see Supplemental Videos S1-S2 and Table 1). (A) Wind-rose plots of fMLP-stimulated WT and Lsc KO neutrophil migration over 15 minutes (n = 60 cells of each genotype). Scale, μm. Lsc KO cells migrate farther and with a more meandering path. (B) fMLP-stimulated Lsc KO neutrophils migrate faster than WT neutrophils. (C) fMLP-stimulated Lsc KO neutrophils migrate with decreased directionality compared with WT neutrophils. The fMLP-stimulated Lsc KO neutrophils also make larger average turns, fewer small turns (≤ 30°), and more large turns (> 30°) turns, compared with WT neutrophils. Data are the mean ± SEM for 60 cells of each genotype from 3 independent experiments.