Rab40b inhibits EPLIN accumulation at the lamellipodia leading edge. (A) Schematic representation of FA and stress fiber distribution in lamellipodia. (B–G) Representative line scans from control (E), FLAG-Rab40b-4A (F), and Rab40-3KO (G) cells plated on collagen-coated coverslips and then fixed and stained with phalloidin–Alexa Fluor 594 (red) and anti-EPLIN (green) antibodies. Boxes mark the region of interest shown in inset. Line marks the region analyzed by line scan (quantifications shown in B–D). EPLIN distance from actin front: control, 1.8 µm ± 1.1; FLAG-Rab40b-4A, 0.68 µm ± 0.33 (P < 0.05); and Rab40-3KO, 0.36 µm ± 0.29 (P < 0.02). n = 5 cells for each cell line.