Tail bleeding time in mouse strains with different mouse and human VWF exon 28 and GPIbα combinations. (A) Bleeding time in 6 mouse strains: M1MA, n = 13; M1HA, n = 17; H1MA, n = 12; H1HA, n = 17; KO1HA, n = 4; H1KOA, n = 5 (Table 1). Mouse strains were tested as described in “Materials and methods.” (B) The amount of blood lost into collection tubes was determined by measuring hemoglobin content. The number of mice (n values) are the same as for the bleeding time test, except for M1HA (n = 16). Data are shown with median and interquartile range. Statistical analysis in panel A was performed with the Kruskal-Wallis nonparametric test followed by Dunn’s multiple comparison test; in panel B, one-way ANOVA followed by Tukey’s multiple comparison test was used. *P < .05; **P < .0; ***P < .001.