In established RA, analysis by multiple regression with correction for age, sex and disease duration revealed a significant association between TNF-RII genotype and the levels of sTNF-RI (P for trend = 0.01) and sTNF-RII (P for trend = 0.03) in the order TT > TG > GG. Here, TNFRSF1B is linked to rheumatoid arthritis.