Cumulative lymphocyte rolling velocities in PLN HEVs of WT and C2GlcNAcT-I^-/- mice. Percentages of (A-B) T cells and (C-D) B cells that rolled in order III (A, C) or order IV (B, D) HEVs at or below a given velocity are graphed as a function of V_roll.n = total number of cells/venules/mice analyzed per group.