In UKRAGG AUCs for the SNP, HLA, HLA-SNP, HLA-smoking and HLA-SNP-smoking models in discriminating between ACPA-positive RA and controls comprised 0.617 (95% CI 0.577–0.656), 0.748 (95% CI 0.731–0.765), 0.756 (95% CI 0.723–0.790), 0.813 (95% CI 0.782–0.845) and 0.857 (95% CI 0.804–0.910), respectively (Figure 3). Here, PRTN3 is linked to rheumatoid arthritis.