It has been reported that the levels of various inflammatory cytokines and chemokines, such as IL-2, IL-4, IL-5, IL-6, IL-7, IL-10, IL-13, IFN-γ, granulocyte colony-stimulating factor, granulocyte macrophage colony-stimulating factor, monocyte chemotactic protein-1 and macrophage inflammatory protein-1β, are increased in the sera of RA patients [41]. This evidence concerns the gene IFNG and rheumatoid arthritis.