Polymorphisms of the Human Platelet Antigens HPA-1, HPA-2, HPA-3, and HPA-5 on the Platelet Receptors for Fibrinogen (GPIIb/IIIa), von Willebrand Factor (GPIb/IX), and Collagen (GPIa/IIa) Are Not Correlated With an Increased Risk for Stroke | Synapse