It was reported that bone resorption of RA patients is characterized by a high serum concentration of the bone remodeling and resorption markers MMP-9 [37] and CTSK [38] through the synergistic impact of TNF-α, IL-1, and IL-6 [39], whereas IL-6 alone probably plays only a minor role. The gene discussed is TNF; the disease is rheumatoid arthritis.