Rap1b loss promotes transendothelial migration via transcellular route. (A, top) Representative immunofluorescence images showing paracellular and transcellular migration of neutrophils, identified using VE-cadherin, ICAM-1, and Gr-1 staining. Bar, 20 µm. (bottom) Percentage of WT and Rap1b^−/− neutrophils showing diapedesis via paracellular and transcellular route and relative percent neutrophils using paracellular and transcellular route (mean ± SD). Data are cumulative from 4 independent experiments with more than 750 cells showing transendothelial migration. (B, top) Representative images of transmigratory cups, percentage of WT and Rap1b^−/− neutrophils encircled with ICAM-rich transmigratory cups. Mean ± SD. n = 3 independent experiments. **, P < 0.01; ***, P < 0.001; NS, not significant using unpaired Student’s t test. Bar, 10 µm.