In the liver laceration FVIII reduced bleeding in hemophilia mice from 40.7 μL/g to 25.0 μL/g (versus 29.0 μL/g in saline-treated wt-BALB/c mice) and in the tail clip model FVIII reduced bleeding from 35.7 μL/g to 4.4 μL/g (versus 4.2 μL/g in saline-treated wt-BALB/c mice). This evidence concerns the gene F8 and hemophilia.