Binding of ¹²⁵I-vWF to WT or M239V in the presence of various concentrations of botrocetin. The experiment was essentially the same as that described in Fig 3, except that botrocetin was used to induce vWF-GPIbα binding. Nontransfected (NT) medium was used as a control. There was no significant difference between WT and M239V in terms of botrocetin dose-dependent binding of ¹²⁵I-vWF. Two-way factorial ANOVA showed no significant interaction between the effect of botrocetin concentration and the recombinant GPIbα fragments (WT or M239V).