von Willebrand factor synthesized by endothelial cells from a patient with type IIB von Willebrand disease supports platelet adhesion normally but has an increased affinity for platelets - de Groot, P G; Federici, A B; de Boer, H C; d'Alessio, P; Mannucci, P M; Sixma, J J (Proc Natl Acad Sci U S A, 1989)