Dysregulated TNFR-signaling pathways or sustained production of TNFα has been involved in the pathogenesis of many chronic inflammatory diseases and anti-TNFα therapy has demonstrated efficiency in the treatment of severe forms of rheumatoid arthritis, Crohn’s disease, ulcerative colitis, psoriasis, psoriatic arthritis, ankylosing spondylitis and juvenile idiopathic arthritis. This evidence concerns the gene TNF and ankylosing spondylitis.