Consequences of miR-223 knockout on platelet SMOC1 expression and responsiveness to thrombin. (A) SMOC1 and β1-integrin (β1) levels in washed platelets from WT (y/+) and miR-223^y/− (y/−) mice; n = 14 per group. ***P < .001, Student t test. (B) Thrombin (Thr; 1 U/mL; 10 minutes)–induced phosphorylation of β3-integrin on Tyr773 (pY773) in platelets from WT (y/+) and miR-223^y/− (y/−) mice; n = 5 per group. ***P < .001, ANOVA and Bonferroni test. (C) Thrombin-induced aggregation in platelets from WT (y/+) and miR-223^y/− (y/−) mice in the presence of solvent (Sol), an antibody against SMOC1 (abS1; 0.625 ng/µL), or an anti–β-actin antibody (abβ; 0.625 ng/µL); n = 8 animals per group. **P < .01, ***P < .001, 2-way ANOVA and Bonferroni test.