HAPC1573 (1573) reduces tail bleeding time of PROC^+/+;F8^−/− mice.PROC^+/+;F8^−/− mice (A) and F8^−/− mice (B) were treated with either 0.05 IU per mouse of FVIII, 20 µg per mouse of anti-human APC antibody HAPC1573, or both in combination 30 minutes before the procedure. Tail tip bleeding time was recorded for a maximum of 20 minutes to avoid mortality caused by over bleeding. Pretreatment with PBS was used as a negative control. Data were expressed as mean ± SD. n = 6 mice per group. **P < .01; ***P < .001, ns, P ≥ .05 (1-way ANOVA test). ns, not significant; WT, tail bleeding time of WT mice.