Coagulation-induced GPVI shedding is mediated by FXa. (A) Coagulation induced by RVV (1:1 molar ratio with FX) in citrated PRP in the absence or presence of 0.2 U/mL enoxaparin or 20 U/mL hirudin. (B) Washed platelets (10⁹/mL) resuspended in FX-deficient plasma with or without added purified FX (10 μg/mL, final concentration). Coagulation was induced by recalcification, and sGPVI was measured as described in Figure 1 legend.