We directly sequenced the entire DR3 genome of patients with RA, and found a variant of the DR3 gene that contains four single nucleotide polymorphisms (SNPs) and one 14-nucleotide deletion, which we termed polymorphisms a, c, d, e, and b (Fig. 1A; SNPa, rs11800462; SNPb, rs763855745; SNPc, rs3138153; SNPd, rs3138155; SNPe, rs3138156, as registered GenBankTM accession No. AB051850.1 to DR3 and AB051851.1 to variant DR3). Here, TNFRSF25 is linked to rheumatoid arthritis.