CXCL1 and systemic-onset juvenile idiopathic arthritis: In this explorative study, we not only confirmed the previously reported sJIA biomarkers IL6, IL18, S100A12 and OSM, but also identified new potential biomarkers CASP8, CCL23, CD6, CXCL1, CXCL11, CXCL5, EIF4EBP1, KITLG, MMP1, OSM, SIRT2, SULT1A1 and TNFSF11 that characterized sJIA patients in active and inactive phases.