However, Crohn’s disease has also been associated with the presence of activated NF-κB and inflammatory NF-κB target gene products in epithelial cells and lamina propria macrophages (193, 194), resulting in a protracted controversy as to whether Crohn’s disease-linked mutations in NOD2 diminish or enhance its activity in the context of the disease. This evidence concerns the gene NOD2 and Crohn disease.