Dimerized β₂GPI increases thrombus size, carotid artery, and peritoneal macrophages TF activity in mice through an interaction with ApoER2. ApoER2^+/+ (filled bars) or ApoER2^−/− (open bars) mice were injected with dimeric β₂GPI or monomer β₂GPI as control. (A) Thrombi were induced in the animals, and thrombus size was measured in square microns (μm²). The data are expressed as mean ± SD (5-10 animals were used per group). (B) In peritoneal macrophages as described in “Statistical analysis,” TF activity was determined with a commercial chromogenic assay for Xa formation. Results are expressed as means ± SEM in pM · mg⁻¹ · mL⁻¹. Experiments were assayed in duplicate and repeat thrice. ¶Statistically different from apoER2^+/+ treated with control; (A, P = .011 and B, P = .023). *Statistically different from apoER2^+/+ treated with dimer (A, P = .007 and B, P = .013). **Statistically different from apoER2^−/− treated with dimmer (A, P < .0001 and B, P < .0001).