[29], [30] In Hemophilia B, a dose of 15–20 U/kg of Factor IX was sufficient to cause disseminated intravascular coagulation (DIC). Others indicate the presence of IgE (Th2 dependent) in Pompe gene therapy and we have previously found the production of IL-4 while assessing Th2 immunity in response to dominant rhGAA epitopes in the GAA-/-129SVE Pompe model.[10], [11] We found that lowering the dose of rhGAA resulted in significant reduction of anti-rhGAA IgG1, IgG2a, IgG2b and IgM antibody responses in the animal models tested. The gene discussed is IGHE; the disease is hemophilia B.