IL6 and juvenile idiopathic arthritis: Several other genes are probably involved in JIA pathogenesis; indeed elevated synovial and sera levels of TNF-α and other inflammatory cytokines as interleukin-1 (IL-1), interleukin-6 (IL-6), and interferon-gamma (INF-γ) in JIA subjects are likely related to abnormal expression of genes for cytokine production and regulation [26, 33].