No significant difference was observed in CCL21 serum concentrations between patients with JIA with oligoarticular course (median 229.2 pg/ml, range 67–3948 pg/ml), patients with JIA with polyarticular course (median 378 pg/ml, range 65–5146 pg/ml) and age-matched healthy controls (median 282.2 pg/ml, range 76–2349 pg/ml, P = 0.3; Kruskal–Wallis ANOVA test). Here, CCL21 is linked to juvenile idiopathic arthritis.