In addition to this, polymorphism studies have shown relationships between the IL-12B and IL-23R genes and various autoimmune diseases such as multiple sclerosis, psoriasis, rheumatoid arthritis (RA), inflammatory bowel disease, ankylosing spondylitis, sarcoidosis, arthritis and Crohn’s disease [8,9,10]. This evidence concerns the gene IL23R and rheumatoid arthritis.