DUOX2 and inflammatory bowel disease: However, DUOX2 is not yet reported as a risk factor for IBD in adult patients, for example, by genome-wide association studies (GWAS) [15,17], and mice with non-functional DUOX1 and DUOX2 by deletion of their maturation factors DUOXA1 and DUOXA2 in the entire body did not display an altered colitis susceptibility [9].