IL-18 levels, 2000–5000 pg/mL, that are at least 10-fold higher than the levels in healthy controls, are suggested to be the cut-off values for the differentiation of systemic juvenile idiopathic arthritis (sJIA) and adult-onset Still’s disease (AOSD) from other pathologies, e.g., Kawasaki Disease, FMF, TRAPS, other subtypes of JIA, SLE, JDM, and leukemia (Shimizu et al., 2022) [39]. This evidence concerns the gene IL18 and systemic-onset juvenile idiopathic arthritis.