The SNP rs11209026 (Arg381Gln) leads to replacement of Arg with Gln within the IL23R-binding domain for the JAK2 kinase, and therefore may change the downstream signaling pathways and responses to IL-23.19,26 The much less common glutamine allele seems to protect against some autoimmune diseases such as inflammatory bowel disease, psoriasis and ankylosing spondylitis.19,27 The association of SNP rs11209026 with a number of immune-related diseases such as inflammatory bowel disease,28 psoriasis,29 Crohn's disease30 has also been reported. This evidence concerns the gene IL23R and ankylosing spondylitis.