TF and Venous thrombosis: In summary, immune cells precipitate venous thrombosis through the following pathophysiological pathways: neutrophils extrude NETs and activate FXII to FXIIa to trigger intrinsic coagulation; monocytes release microparticles that deliver TF to trigger extrinsic coagulation; and mast cells promote platelet activation and adhesion to support immunothrombosis (Figure 2 and Table 1).