In บางรูปลักษณะ of the การประดิษฐ์, the human
IgG4 บริเวณคงที่ is modified at amino acid positions Ser228, Leu235, and Asn297 (e.g., S228P/L235E/N297A). (EU index of Kabat et al 1991 Sequences of Proteins of
Immunological Interest). In other รูปลักษณะ of the การประดิษฐ์, the antibody is of human IgG4 subclass and lacks glycosylation. In these รูปลักษณะ the glycosylation can be
eliminated by mutation at position 297 (Kabat numbering), for example N297A. In other รูปลักษณะ, the glycosylation can be eliminated by production of the antibody in a host cell that lacks the ability for post-translational glycosylation, for example a bacterial or
yeast derived system or a modified mammalian cell expression system.