VWF and von Willebrand disease (hereditary or acquired): Consequently, the VWF:RCo/VWF:Ag and VWF:CB/VWF:Ag ratios are <0.7, mirroring the pattern observed in type 2A von Willebrand disease (VWD) [6,7], and could serve as routine screening tools to evaluate VWF function and identify the loss of VWF large multimers [8].