IFNG and juvenile idiopathic arthritis: The following cytokines were excluded in JIA-TMJ serum due to more than 60% of the samples were below limit of detection: IL-1ra, IL-1b, IL-2, IL-5, IL-6, IL-7, IL-10, IL-12, IL-15, GM-CSF, IFNγ, FGF-basic, VEGF