ATG16L1 and inflammatory bowel disease: IBD is a multifactorial disorder with genetic susceptibility, immunological predisposition and environmental triggers.6, 7 To date, >150 genetic loci have been linked to IBD by association studies.8 Variants in genes that affect bacterial handling (such as nucleotide-binding oligomerization domain-containing protein 2 NOD2) and autophagy (such as ATG16L1 or IRGM) are associated with polygenic IBD.