IL23R and rheumatoid arthritis: 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.