The mechanistic relationship between gene variants in NOD2 and Crohn’s disease pathogenesis is unclear, but could involve defective epithelial defenses, disruption of Paneth cell function, alterations in the gut microbial community, and/or defects in autophagy (reviewed in (Al Nabhani et al. 2017; Feerick and Mckernan 2017)). The gene discussed is NOD2; the disease is Crohn disease.