WASP-KO NK cells show normal accumulation of talin, Arp2/3, and vinculin, but not actin. Ex vivo, IL-15–, or IL-2–activated splenic NK cells from WASP-KO mice were incubated with ICAM-1 (IC-1) or PLL beads, fixed, permeabilized, and stained for talin (A), Arp2/3 (B),vinculin (C), or actin (D) and analyzed by confocal microscopy as in Figure 1. The percent fluorescence intensity of staining at the contact site between an NK cell bound to an (▬) ICAM-1– or (▭) PLL-coated bead was calculated as in Figure 1 and shown in bar graphs to the right of confocal images. Error bars indicate SEM, n = 10 per condition. ***P < .005, **P < .01, and *P < .05 compared with corresponding PLL condition.