The combination of PT and type 2B mutations significantly reduces translocation velocities. (A) Mean translocation velocities for interacting healthy or PT-VWD platelets (n = 30 to 40 cells) on the indicated VWF-A1 substrates (100 μg/mL). Data represent the mean ± SD for 3 to 4 independent experiments performed in duplicate. (B) Translocation velocities of WT or type 2B–coated beads (100 μg/mL) on the indicated platelet substrates. Beads that had accumulated on surface-immobilized platelets were subjected to incremental increases in wall shear stress and rolling velocities calculated for a minimum of 50 beads over 10-second intervals. Data represent the mean ± SD for 3 to 4 independent experiments performed in duplicate.