The abundance of non-galactosylated (agalctosylated; G0) serum IgG Abs that lack galactose and terminal sialic acid residues positively correlates with the disease severity in rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) (3–25), whereas alleviated disease activity in RA patients during pregnancy or after anti-TNF treatment is associated with increased levels of sialylated IgG Ab (6, 17, 20, 26–28). The gene discussed is TNF; the disease is rheumatoid arthritis.