Effect of blocking GPIIb/IIIa + vβ3 receptors on thrombin generation in the absence and presence of fibrin clots. Thrombin generation was triggered at t = 0 in PRP (adjusted to 3 × 10⁸/mL) by recalcification and addition of tissue factor. (□) Control; (▪) three fibrin clots added at t = 0; (∗) PRP preincubated with antibody 7E3 (anti-GPIIb/IIIa + vβ3; 20 μg/mL); (▴) preincubation with 7E3 and fibrin clots added.