In addition, the serum levels of IL-18Rα complex, IL-13 and IFN-γ were not significantly associated with the Steinbrocker functional classification score, the joint damage score, DAS28 (CRP level), DAS28 (ESR), HAQ value, WBC count, CRP level or smoking status in RA patients. The gene discussed is IL18R1; the disease is rheumatoid arthritis.