Blood loss following tail clipping assay in HA mice after AAV injection. HA/CD4-deficient mice received AAV vectors at a range of doses and were grouped according to the circulating FVIII-RH or FVIII-BDD levels determined at week 8 after injection. The numbers of mice in each group are indicated. Control groups included untreated HA/CD4-deficient mice or hemostatically normal C57BL/6 mice. Total blood loss (μL) was measured after tail transection at a 3-mm diameter, and blood was collected for 10 minutes. n.s., not significant.