HUVECs were stimulated with IL-4 as described in Fig 1. Before assembly of the flow chamber, HUVECs were treated for 10 minutes at 37°C with HBSS/A alone or HBSS/A containing 5 μg/mL of G1, an MoAb directed against P-selectin. In some experiments, eosinophils were also pretreated 10 minutes at 37°C with either 2 μg/mL of H2/1, an anti–α4-integrin MoAb; 5 μg/mL of an anti–β2-integrin MoAb; or both antibodies before perfusion over IL-4–stimulated HUVECs. To determine the percentage of rolling and adherent cells, images were captured 5 seconds apart and the cells that were stationary during that time were considered adherent. Cells that moved at least 1 cell diameter were considered rolling. The data represent the mean ± SD of at least two experiments.