Effect of aPL Abs on TF activity in carotid artery homogenates in A2^−/− mice. A2^−/− or A2^+/+ mice were treated with IgG-APS, IgG-NHS (A), 4C5, anti-A2 MoAb, or MuMoAbC as control (B). TF activity was determined in homogenates of carotid arteries using a chromogenic assay, and data expressed as means ± SD in pmol/mg per mL⁻¹ protein. Experiments were assayed in duplicate and repeated thrice. ¶Statistically different from A2^+/+ mice treated with IgG-NHS (A; P = .015) or MuMoAbC (B; P = .001). *Statistically different from A2^+/+ mice treated with IgG-APS (A; P = .026) or 4C5 (B; P = .007). **Statistically different from A2^−/− mice treated with IgG-APS (A; P = .046) or 4C5 (B; P = .002).