Inhibition of Src kinases and PLC decreases VWF-mediated thromboxane production. Platelets were unstimulated (control) or stimulated with VWF/ristocetin (8 and 300 μg/mL, respectively) in the absence or presence of either (A) the Src kinase inhibitor PP2 (10 μM) or (B) the PLC inhibitor U73122 (4 μM). Platelets were then processed for measurements of thromboxane production, as described in “Materials and methods.”