In SLE this SNP and two other linked SNPs, the SNPs rs2070197 in the 3′-UTR of IRF5 and rs10488631 located ∼5 kb downstream of IRF5, give particularly strong association signals.35 Two recent genome-wide association studies failed to detected an association with RA for the SNP rs10488631 or its proxies44, 45 and in our study on IBD we did not detect an association with the SNP rs10488631 either.27 Thus it appears that in SLE there are two groups of independently associated polymorphisms in the IRF5 gene region,46 whereas in MS, RA and IBD association from only one of these groups is observed. This evidence concerns the gene IRF5 and rheumatoid arthritis.