Our study is the first to show that rhIL-37 could downregulate expressions of the critical pro-inflammatory cytokines TNF-α, IL-6, and IL-17 after LPS stimulation in PBMCs of sJIA patients, which have no effect on the productions of the pro-inflammatory cytokines in PBMCs of healthy controls. The gene discussed is IL17A; the disease is systemic-onset juvenile idiopathic arthritis.