Increased firm adhesion of α4-R/AGFFKR lymphocytes in vivo to PP venules. Adhesive interactions of WT and α4-R/AGFFKR lymphocytes to PP venules in WT recipient mice were studied using epifluorescence intravital microscopy. Rolling (A) and sticking (B) fractions as well as rolling velocity (C) are shown. Data are mean plus or minus SEM of 9 different PP venules analyzed per group in 2 independent experiments. *P < .05 versus WT.