To investigate further potential explanations for the increased HBD2 production in response to LPS in CD and UC but not HC, we sequenced the promoter region of the DEFB4 gene, to ask whether IBD patients had polymorphisms at potential NF-κB binding sites, as identified by Transcriptional Element Search Software (TESS) [38]. Here, NFKB1 is linked to inflammatory bowel disease.