Have genome-wide association studies or knockout mice more reflected the true nature of inflammatory bowel disease?

Abstract

Since the finding of the first gene, NOD2 (also known as IBD1 or CARD15) associated with inflammatory bowel disease (IBD) in 2001,1,2 great progress has been made in recognizing more susceptible genes, especially after the introduction of the genome wide association study (GWAS) in recent years. A recent meta-analysis of 15 GWAS on IBD has revealed 163 loci associated with IBD,3 which has been far more than reported for any other complex disease and thus has been served as a splendid example for the great achievements in genetic analysis of complex disease. However, there seems a big discrepancy between the results of the GWAS and the knockout mice. For instance, the finding of the NOD2 gene in 2001 has been celebrated as a big …