The left-right determination factor (LEFTY) and bone morphogenetic protein 8b (BMP8B) are part of the TGF-β superfamily and influence TGF-β signaling which has an important role in maintaining mucosal immunity homeostasis in the bowel [33] and has been shown to be dysregulated in IBD [34]. Here, TGFB1 is linked to inflammatory bowel disease.