Specificity of the effect of 4N1K and TS1 on platelet aggregation on collagen. Human platelets prepared as in Fig 2 were allowed to adhere to immobilized collagen after pretreatment for 15 minutes with (A) anti-2 MoAb, P1E6 (10 μg/mL) + 4N1K (50 μmol/L); or (B) B6H12 F(ab)₂ (100 μg/mL) + 4N1K (50 μmol/L). For (C) through (H), mouse platelets were processed as for human platelets (see Materials and Methods). (C, E, and G) Platelets from IAP-deficient mice; (D, F, and G) platelets from wild-type mice. (C and D) 4NGG (50 μmol/L); (E and F) 4N1K (50 μmol/L); (G and H) human TS1 (50 μg/mL).