A role for autophagy in supporting a balanced immune reaction at this interface is supported by the association between variants in autophagy genes (NOD2, ATG16L1, IRGM, ULK1, and LRRK2) and inflammatory bowel disease (IBD)309, a debilitating disease of the GI tract that involves abnormal reactions against microbes. Here, NOD2 is linked to inflammatory bowel disease.