VWF and von Willebrand disease (hereditary or acquired): The main components in diagnosing vWD involve quantitative and qualitative measurements of vWF and FVIII: Factor VIII coagulant activity (FVIII:C)—measures functional activity of factor VIII; VWF antigen (VWF:Ag)—measures the amount of VWF; Ristocetin co-factor (VWF:RCo)—measures the functional activity of VWF [22].