IRF4 and rheumatoid arthritis: Because some IRF proteins (e.g., IRF3 and IRF4) can induce inhibitory M2 phenotypes59, the approach we describe here could also be used to develop injectable nanomedicine configured to treat autoimmune diseases where inflammatory macrophages play key roles in the pathogenesis, such as systemic lupus erythematosus, rheumatoid arthritis, Sjogren's syndrome, multiple sclerosis, and inflammatory bowel disease60.