For example, in Crohn’s disease, where ATG16L1 rs2241880 represents a widely established genetic risk factor,7,42 the G-allele is associated with increased small intestinal ER-stress and GRP78 expression, most notably in intestinal Paneth cells.7 Interestingly, Paneth cells also appear during the development of complete intestinal metaplasia, and we found that ER-stress accumulation was most noticeable in these Paneth cells within IM tissues, although this was not associated with ATG16L1 rs2241880 status per se. This evidence concerns the gene ATG16L1 and Crohn disease.