In patients with IBD, increased intercellular adhesion molecule-1 (ICAM-1) protein promotes the recruitment of large numbers of leukocytes to sites of intestinal inflammation, whereas upregulation of claudin-2 expression induces a reduction in and the redistribution of epithelial TJ proteins, which increases the cytokine level and barrier dysfunction [105,106,107]. This evidence concerns the gene ICAM1 and inflammatory bowel disease.