A number of studies have shown an association between IBD susceptibility and the nucleotide-binding oligomerization domain 2 gene (NOD2, also known as CARD15), interleukin-23 receptor gene (IL23r), organic cation transporter novel type 1 gene (OCTN1), and the intergenic region (IGR) variants [6-9]. Here, NOD2 is linked to inflammatory bowel disease.