ICAM-2 exhibits both a luminal and EC junctional expression profile in venules in vivo. (A) Unstimulated cremaster muscle tissues from WT mice were immunostained for ICAM-2 and analyzed as detailed in “Immunofluorescence labeling and analysis of cremaster muscle tissues by confocal microscopy.” The specificity of binding of the anti-ICAM-2 mAb was confirmed in tissue samples obtained from ICAM-2–deficient mice in which the tissues were double stained for ICAM-2 and α–smooth muscle actin, the latter assisting in the identification of venules. (B) Unstimulated cremaster muscle tissues from WT mice were immunostained for JAM-A and PECAM-1 as detailed in “Immunofluorescence labeling and analysis of cremaster muscle tissues by confocal microscopy.” Samples were observed using a Zeiss LSM 5 PASCAL confocal laser-scanning microscope and analyzed using IMARIS software. Images are representative of 2 half-vessels per mouse, from 4 mice.