1. From the Sanquin (J.F.W.K.), Blood Bank region South-East, Maastricht, and the Department of Biochemistry (S.J.H.W., T.H., J.W.M.H., E.M.B., T.L.), Cardiovascular Research Institute Maastricht, Maastricht University, the Netherlands; and the Laboratory for Thrombosis Research (H.U., H.D.), K.U. Leuven, Campus Kortrijk, Belgium.