HSPA5 and Crohn disease: 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.