NOD2 and Crohn disease: Common Crohn’s disease-associated NOD2 variants expressed in HEK293T kidney cells are unable to detect MDP and activate NF-κB (178) and monocytes from Crohn’s disease patients with the 1007fs variant displayed defects in the secretion of TNFα, IL-6, IL-8, and IL-10 (179, 180) and many of these NOD2 variants seem to act recessively (181).