The NOD2 locus, a cluster of chemokine genes (CXCL1-3, CXCL5-6, and CXCL8), and two receptors for these chemokines (CXCR1 and CXCR2), represent examples of enhancers linked with neighboring TSSs of genes associated with IBD pathogenesis (Fig. 4a–c). This evidence concerns the gene NOD2 and inflammatory bowel disease.