The IL-23R gene is located on the chromosome 1p31.3 that encodes the receptor for IL-23.19 The association of the IL-23R gene polymorphisms with several inflammatory and autoimmune diseases such as ankylosing spondylitis,20 psoriatic arthritis,21 allergic rhinitis,22 rheumatoid arthritis,23 and systemic lupus erythematosus24 has been reported. The gene discussed is IL23R; the disease is ankylosing spondylitis.