Addition of DHCB (causes α₄β₁ expression in the presence of chemotactic stimuli) had no further effect on the number of rolling neutrophils on TNFα-treated endothelium (A). Neutrophil adhesion (B) was further increased (doubled) relative to neutrophils not treated with DHCB. (▪) Untreated; (▵) DHCB-treated. *P < .05 relative to treated cells.