IGHG3 and systemic lupus erythematosus: Significant decreases in the serum anti-nuclear IgG3 and anti-dsDNA IgG3 levels (Figure 4E) as well as in the spleen weight: body weight ratio (Figure 4F) were also observed in lupus IgG1-injected MRL-lpr/lpr mice at 19 weeks of age, when compared with those of control IgG1-treated and non-treated groups.