IFNG and rheumatoid arthritis: In RA pathogenesis, IL-10 does more than only inhibit the production of Th1 cell-generated cytokines (GM-CSF, IL-1, IFN-γ, and TNF-α); it preserves joint tissue, prevents the activity of antigen-presenting cells, and suppresses the production of IL-18 mRNA (Lin et al., 2013).