Activated partial thromboplastin times (aPTTs in s) of C3H/HeJ hemophilia B mice treated with hF.IX-derived peptide 2A-54 (▴) or saline control (•) after hepatic AAV-hF.IX gene transfer. (A) Four weeks. (B) Twelve weeks. (C) Twenty weeks. Each data point represents an individual animal. Horizontal bars show average antibody titers. Numbers of mice are indicated for each cohort and time point.P values are indicated. Coagulation times were greater than 60 seconds for pooled plasma from untreated C3H/HeJ hemophilia B mice and were 25 to 35 seconds for pooled wild-type C3H/HeJ plasma. These parameters are indicated as dotted horizontal lines.