It is well reported that there is increased expression of chemokines in the active phases of IBD, including IL-8, monocyte chemoattractant protein (MCP)-1 and MCP-3, and macrophage inflammatory proteins (MIP), which are responsible for the recruitment of different leukocyte effector populations, by controlling their adhesion and migration across the endothelium in sites of inflammation. The gene discussed is CCL2; the disease is inflammatory bowel disease.