Since large amounts of type 1 inflammatory cytokines, such as IFNγ, tumor necrosis factor α, IL-15, and IL-18, have been detected in JIA synovium [7], it is likely that these cytokines act in concert, sustaining the local proinflammatory responses and up-regulating CXCL10 expression. This evidence concerns the gene IFNG and juvenile idiopathic arthritis.