Transendothelial migration of T cells. Microphotographs demonstrate immunostaining for the T-cell marker CD3 in the liver tissue of a sham-operated mouse (A), a JAM-A^+/+ mouse after I/R (90/140 minutes) (B), and a JAM-A^-/- mouse after I/R (C, left). Extravascularly localized cells (arrows) were quantified in 10 high-power fields at microscope magnification × 400 (objective 40×/0.75) and (right) expressed as number of cells per square millimeter of liver surface (I/R-JAM^+/+: JAM-A^+/+ mice after I/R; I/R-JAM^-/-: JAM-A^-/- mice after I/R; and I/R-eJAM^-/-: endothelial JAM-A^-/- mice after I/R). n = 6 animals per group; mean ± SEM; ^*P < .05 versus sham-operated group.