The minor (G) allele of rs3761847 in the TRAF1/C5 locus, which is a susceptibility factor for RA related to TNF signaling, was associated with a poor response to anti-TNF treatment at six months, using either the absolute change in DAS28 or the proportion of good responders and nonresponders as outcomes. This evidence concerns the gene TRAF1 and rheumatoid arthritis.