hF.IX expression levels and anti-hF.IX antibody formation after AAV2-hF.IX hepatic gene transfer in rhesus macaques receiving MMF, sirolimus, and daclizumab and in nonimmunosuppressed controls. Time 0 represents baseline samples; dotted vertical line shows the time IS was withdrawn. Each line is representative of one individual animal. All animals received 8 × 10¹² vg/kg of an AAV-2-hF.IX vector infused through the hepatic artery. Solid symbols indicate animals receiving a course of IS consisting of MMF, sirolimus, and daclizumab; open symbols, non-IS control animals. (A) Plasma human F.IX levels. (B) Plasma antihuman F.IX total IgG levels.