Inhibitor formation in normal and HB mice. The inhibitor activity for the sample from each mouse with the highest antibody level is plotted versus the anti-hFIX IgG level for that sample. (A-D) Values are shown for mice of the indicated strain that did not receive gene transfer and were challenged with 10 doses of 30 IU hFIX without adjuvant. (E) HB mice that did not receive gene transfer were challenged with 10 injections of 30 IU/kg hFIX without adjuvant (•) or 2 doses of 30 IU/kg hFIX with adjuvant (○). (F) HB mice were treated with the very low dose of RV. One mouse (the time course of antibody levels for this mouse is shown as a ○ in Figure 3G) was challenged with 10 doses of hFIX without adjuvant and 1 dose of hFIX with adjuvant (▴). The other mice (shown in Figure 3H) were stimulated with 2 doses of hFIX with adjuvant and are shown as ○ here.