ostalowska et al. found a significant increase in the activity of antioxidant-related enzymes in the synovial fluid in patients with knee osteoarthritis (superoxide dismutase, both isoenzymes zinc-copper superoxide dismutase and manganese superoxide dismutase) in patients with knee osteoarthritis [51], leading to a significant decrease in synovial fluid viscosity and further promoting the progression of knee osteoarthritis. The gene discussed is SOD2; the disease is osteoarthritis, knee.