All of these genes have been reported as having pathogenic mutations in non-IBD diseases (ICAM1, ITK, LRRK2, NOD2, and INPP5D in primary immunodeficiency; EGR2 in systemic lupus erythematosus; PDGFD, IL33, and RGS1 in autism spectrum disorder; TLR4 in type 2 diabetes, gastritis and susceptibility to infectious diseases; VDR in Vitamin D-resistant rickets) in the Human Gene Mutation Database (HGMD) Professional version12. Here, NOD2 is linked to systemic lupus erythematosus.