Adhesion of RBCs from younger versus older sph/sph and sph^Dem/sph^Dem mice to TSP. Washed RBCs from sph/sph (A) and sph^Dem/sph^Dem (B) mice in 4 different age groups (3-4 weeks, 6-8 weeks, 12-16 weeks, and 20-24 weeks old) were perfused through flow chambers coated with human TSP as described for Figure 1. Adherent RBCs/mm² are depicted as mean ± SEM for each age group. Stroke incidence for the same groups of mice used for adhesion measurements is indicated above the x-axis of each graph. Numbers of measurements for RBC adhesion to TSP in each age group are indicated in parentheses below age group label on x-axis. *P < .005 versus 12 to 16 weeks and/or 20 to 24 weeks.