Forty six tag SNPs which capture 100 SNPs in the IRF2 region (minor allele frequency ≥0.05) with r2≥0.8 were selected, and a case-control study for the tag SNPs was conducted on the discovery set which consists of 501 Japanese patients with SLE and 551 healthy Japanese controls. This evidence concerns the gene IRF2 and systemic lupus erythematosus.