VWF and hemophilia A: Indeed, it was complicated by the multimeric nature of VWF and the notion that VWF circulates in complex with coagulation factor VIII (FVIII), the protein that is associated with hemophilia A. The technical difficulties that needed to be addressed have nicely been put in context in several personal anecdotes describing the events that led to the discovery in the early 1970s that VWF and FVIII are separate proteins and that VWF is a multimeric protein.3–5 The identification of VWF as a plasma component that is associated with VWD provided the basis for numerous additional studies.