IRF5 signaling has been known to induce various inflammatory cytokines and immune responses and IRF5 deficiency ameliorated the symptoms of several systemic lupus erythematosus mouse models, such as MRL/lpr and pristane models and K/BxN serum-transfer arthritis in one of the rheumatoid arthritis mouse models [31,32,33,34]. The gene discussed is IRF5; the disease is rheumatoid arthritis.