REL encodes the c-rel protein, a member of the nuclear factor-κB family of transcription factors involved in the autoimmune response via regulation of the expression of cytokines, anti-apoptotic molecules and cell cycle modulators.1 Expression of c-rel, which is restricted to mature haematopoietic cells, has been described in patients with systemic lupus erythematosus (SLE) and inflammatory bowel disease.2 3 Associations of the REL gene with celiac disease4 and rheumatoid arthritis (RA)5 have been reported. Moreover, Rel knockout mice do not develop autoimmune diseases such as experimental autoimmune encephalomyelitis,6 collagen-induced arthritis or type I diabetes.7 Last year Gregersen et al described the association of the intronic single nucleotide polymorphism (SNP) rs13031237G→T in the REL gene as a risk factor for RA in an expansion of previous genome-wide association …