1. From the Laboratory for Thrombosis and Haemostasis (I.A.F., A.I.M.M., G.G., J.-W.N.A.), Department of Hematology, University Medical Center Utrecht and the Institute for Biomembranes (I.A.F., A.I.M.M., G.G., J.-W.N.A.), Utrecht University, the Netherlands; Department of Biochemistry and Human Biology (M.A.H.F., J.W.M.H.), University of Maastricht, the Netherlands; Department of Internal Medicine (T.W.v.H.), University Medical Center Utrecht, the Netherlands.