Effect of α_L and α₄ blockade on normal B-cell motility on, and migration through, HUVECs. Panels A and B show the effect of blocking mAbs on motility on HUVECs, while C and D illustrate the effect of these mAbs on TEM. α_L blockade induced significant inhibition of both motility (P = .0006) and TEM (P = .006), whereas α₄ had no significant effect on normal B-cell motility on (P = .07) or through (P = .08) HUVECs. Asterisk indicates no motile cells. Error bars indicate standard error of the mean.