OLFM4 and inflammatory bowel disease: Besides OLFM4, through SMI we observed other changes that occur in the intestinal epithelium of IBD patients, including the upregulation of anti-microbial mechanisms such as the expression of defensins (DEFA5), lipocalins (LCN2) and enzymes involved in producing reactive oxygen species (DUOXA2) (Fig. 3i; Supplementary Fig. 8d, e).