In this model then, chemokines and chemokine receptors (and particularly CXCR4/SDF-1) may represent an autocrine/paracrine loop that helps maintain mucosal barrier integrity and repair as well as regulating mucosal pathogenesis (including chronic inflammation as seen inflammatory bowel disease and progression to colon cancer) [33] . The gene discussed is CXCL12; the disease is inflammatory bowel disease.