VWF and von Willebrand disease 1: We included 158 subjects diagnosed with type 1 VWD, who had a mean historical VWF:Ag level of 0.35±0.13 IU/mL (mean ± standard deviation), VWF:CB of 0.29±0.13 IU/mL, and VWF:Rco of 0.27±0.14 IU/mL.