S100A9 and juvenile idiopathic arthritis: Various cytokines (S100A8, S100A9, TTR, sCD14, LAP3, and SAA1) that are present in aqueous humor of JIA-U, were detected in tears of all JIA-U and I-CAU children, with a higher expression of S100A8, sCD14, and SAA1 in JIA-U tears, and a lower expression of S100A9, TTR, LAP3, and MIF in JIA-U tears, as compared to I-CAU tears.