ICAM1 and inflammatory bowel disease: First, NFkB-dependent secretion of pro-inflammatory cytokines in the intestine of IBD subjects was shown to be down-regulated by PAP/Reg3β in endothelial cells, epithelial cells and monocytes.[9] Second, it has been demonstrated that PAP/Reg3β can inhibit leukocyte recruitment into the bowel by monitoring up-regulation of E-selectin, ICAM-1, and VCAM-1.[9] Sustained low intraluminal levels of PAP/Reg3β, therefore, could impact the immunological balance of the intestinal mucosa in these patients, contributing to the pathogenesis of bowel chronic inflammation.