Knockdown of αPIX rescues cell migration in moesin-depleted cells. (A) Control, moesin RNAi, moesin + Vav1 RNAi, or moesin + αPIX RNAi cells were exposed to a 100-nM fMLF gradient. Each trace represents one individual cell (>30 cells per condition). (B and C) Cells were treated as in A. CI (B) and speed (C) were calculated. ***, P < 0.001 (Student’s t test). (D) Control, moesin RNAi, moesin + Vav1 RNAi, or moesin + αPIX RNAi cells were stimulated with fMLF and were visualized with F-actin (top) and DIC (bottom). n > 30 cells per condition. Bars: (A) 100 µm; (D) 10 µm. (E) Cells were treated as in D. Pseudopod lifetime was calculated. **, P < 0.01; ***, P < 0.001 (Student’s t test). Data are representative of (A and D) or are compiled from three independent experiments (B, C, and E; mean and SEM in B, C, and E).