Anti–human factor IX IgG levels in inbred mouse strains differ following injection with AVC3FIX5 vector. Seven strains of inbred mice were injected with 6.8 × 10¹¹ vector particles/kg AVC3FIX5 adenovirus vector and levels of anti–human FIX IgG were measured one month later. Ten males and 10 females from each strain were assessed. Mean IgG anti–human factor IX levels are shown with 95% confidence intervals (CIs) indicated by vertical lines (▴, males; •, females). As shown in the figure, the P values for comparison of antibody levels between C57 and A/J mice by one-way ANOVA were highly significant for both males and females (P < .0001 for either comparison). Pairwise comparisons of C57 mice with C3H, SM, and Balb mice were also statistically highly significant for both males and females (P < .001, not shown). The P values that were statistically significant retained their significance after adjustments by either the method of Dunnett for comparison of multiple groups to a control group (C57) or the Bonferroni correction to prevent type I error in multiple comparisons. Nonsignificant P values (> .45) were observed for one-way ANOVA comparisons of C57 with C57y or DBA mice. Strain abbreviations are C57 (C57BL/6J), C57y (C57BL/6ByJ), DBA (DBA/2J), Balb (Balb/cByJ), SM (SM/J), C3H (C3H/HeJ), and A/J (A/J). MHC H-2 haplotype designations are shown in italics below each strain.