CTRP-1 prevents collagen-induced platelet activation and aggregation. Collagen-induced platelet activation (5 μg/mL collagen I) measured by ATP release (A) and platelet aggregation (B) are inhibited by CTRP-1 (5 μg/mL). The inhibition of platelet aggregation by CTRP-1 is dose dependent (C). For this experiment, PRP was incubated with 1.25 μg/mL collagen I. RU indicates relative units.