Expression of FVIII-RH and FVIII-BDD following AAV-mediated liver gene transfer. The graphs show circulating FVIII antigen (A) and FVIII activity by chromogenic assay (B) in HA/CD4-deficient mice 8 weeks after injection with AAV-FVIII-RH or AAV-FVIII-BDD at the doses indicated (n = 5 to 13 mice per group per dose). Liver sections of HA/CD4-deficient mice injected with AAV-FVIII-BDD (total n = 15) or AAV-FVIII-RH (total n = 14) harvested 14 to17 weeks after vector injection for the determination of (C) AAV DNA content and (D) FVIII-RNA are shown. P values determined by Student t test are shown.