In juvenile idiopathic arthritis (JIA), the most common rheumatoid disorder in pediatrics, an elevation of proinflammatory cytokines, such as IL-1β, IL-6, IL-8, or TNF-α, has been demonstrated in both the serum and synovial fluid of patients with JIA (Gorczyca et al., 2017). Here, TNF is linked to juvenile idiopathic arthritis.