VWF and Von Willebrand disease: Correct diagnosis of von Willebrand disease involves many different methods and this study will only focus on the methods that can be performed on an automated analyzer such as von Willebrand factor (VWF) activity, based on the glycoprotein Ib‐containing gain‐of‐function mutation (VWF:GPIbM), and antigen (VWF:Ag).