Abstract
NOD2, a gene conferring susceptibility to Crohn's disease, has been identified on chromosome 16. Homozygosity for a mutation that truncates the gene increases the risk of Crohn's disease by a factor of 20 to 40. No such mutations have been found in patients with ulcerative colitis. NOD2 has a role in apoptosis and in the recognition of microbial endotoxins.