The cut-off values of serum IL-18 levels for the differentiation of s-JIA from KD, FMF, TRAPS, other subtypes of JIA, SLE, JDM, and leukemia were 4560, 4800, 1685, 1728, 2400, 2125, and 2240 pg/mL, respectively. This evidence concerns the gene IL18 and juvenile idiopathic arthritis.