Comparison of ADP- or thrombin-induced aggregation responses of platelets isolated from WT→WT or β^s→WT mice. (A,C) Mean aggregation responses to EC₅₀ doses of ADP (733nM) and thrombin (0.63 U/mL). (B,D) Representative aggregation responses to the EC₅₀ doses as detected by a laser-particle analyzer. Data are shown as the means ± SEM. *P < .05 compared with WT→WT. n = 5 mice/group.