A recent study by the North American Specialized Coagulation Laboratory Association (NASCOLA; 24 identified a high error rate by participants performing multimer analysis, such that 5% of laboratories reported false loss of HMW VWF multimers in normal samples, 18% reported false loss of high- or medium- and HMW multimers in type 1 VWD samples, and 22% reported a false normal multimer pattern in type 2A VWD samples. Here, VWF is linked to von Willebrand disease 1.