IFNG and systemic lupus erythematosus: In addition, lupus IgG1-injected MRL-lpr/lpr mice exhibited significantly higher serum C3 and complement factors B and H levels (Figure 4G), as well as significantly lower serum IFN-γ, IL-6, and IL-17 levels (Figure 4H) at 19 weeks of age, compared with those of control IgG1-treated and non-treated groups.