Sex difference in rAAV expression is independent of transgene cDNA and promoter. (A) Schematic of rAAV-2 CAGG tsFlk-1 in which the hFIX cDNA of rAAV-2 CAGG-FIX has been replaced with a 2.3-kb tsFlk-1 cDNA (top panel). Stable serum levels of tsFlk-1 assessed by ELISA, 12 weeks after portal vein infusionof1 × 10¹¹ rAAV-2 CAGG tsFlk-1 vector particles in cohorts (n = 6) of male (M) and female (F) B6.CB17-Prkdc-SzJ mice (bottom panel). (B) Schematic of rAAV LSP-FIX in which the CAGG promoter has been replaced with an LSP (top panel). Stable plasma hFIX levels 12 weeks after portal vein infusion of 1 × 10¹¹ rAAV LSP-FIX vector particles in cohorts (n = 3) of male (M) and female (F) B6.CB17-Prkdc-SzJ mice (bottom panel). All transgene expression values are depicted as an average together with the standard error of the mean.