Time course of human F.IX expression in C57Bl/6 Rag-1 knock-out mice. Mice were injected into skeletal muscle with AAV-1 vectors encoding F.IX-WT (), the F.IX variants K5A (), K5A/V10K (▴), or R338A (▪). Vector was injected at doses of 2 × 10¹¹ vg/kg (A) or 1.2 × 10¹² vg/kg (B) at 6 intramuscular sites in the hind limbs. Each line represents average values for the cohort (n = 4 mice). Markers represent mean values (± SD). ^*P ≤ .002 and ^**P ≤ .05 of comparison between F.IX-WT and F.IX-K5A/V10K groups.