In EIRA cTNC5-positive RA was associated with smoking (OR 1.65 vs 1.26) and HLA-DRB1 shared epitopes (OR 4.98 vs 1.68), but not with PTPN22 (OR 1.77 vs 1.44) when compared with the cTNC5-positive/CCP2-negative RA subset (see online supplementary table S3). Here, HLA-DRB1 is linked to rheumatoid arthritis.