It has been revealed that polymorphisms of genes encoding tight junction-associated proteins such as myosin IXB (MYO9B), partition-defective 3 (PARD3), membrane-associated guanylate kinase inverted 2 (MAGI2), guanine nucleotide-binding protein α12 (GNA12) and protein tyrosine phosphatase TCPTP (PTPN2), cell adhesion-related proteins such as E-cadherin (CDH1) and laminin β1 (LAMB1), and mucus layer proteins such as mucin 3A and 19, are associated with the risk of IBD [77,78]. Here, CDH1 is linked to inflammatory bowel disease.