Exploring two hemophilia A experimental models, Lai et al. reported that the N-linked glycosylated rhFVIII produced in BHK cells (Kogenate® FS) was more immunogenic than that produced in CHO cells (Xyntha®) and that incomplete occupancy of N-linked sites led to the formation of IgM- and IgG-FVIII immune complexes [28]. This evidence concerns the gene F8 and hemophilia A.