Eight murine mAbs against human VWF were used. The anti-VWF D'D3 domain mAbs 1C1E7 and 75H4B12 were kind gifts from Dr. Deckmyn (Laboratory for Thrombosis Research, KU Leuven Campus Kortrijk, Kortrijk, Belgium) [25] . Others were all previously produced in our laboratory. SZ129 and SZ130 recognize VWF A1 domain [26] , whereas SZ123 and SZ125 interact with VWF A3 domain [27] . SZ29 and SZ34 are mAbs to VWF, whose epitopes are indefinite because of being directly raised against purified plasma-derived full-length human native VWF [27, 28] . Horse-radish peroxidase (HRP)-conjugated polyclonal rabbit antihuman VWF IgG was purchased from Dako (Glostrup, Denmark). 