P-selectin upregulation is reduced in LAT^−/− platelets and absent in SLP-76^−/− platelets. Washed murine platelets were stimulated with 0.5 U/ml thrombin, 40 nM Cvx, 10 nM Cvx, 20 μg/ml CRP, or 10 μg/ml CRP for 10 min at 37°C in the presence of FITC-α-P-selectin followed by fixation and flow cytometric analysis. Results were then plotted as the percent of platelets staining positive for P-selectin.