Oxidant generation in IBD is usually ascribed to ER stress in Paneth cells, NOX2 in macrophages and mitochondria, although DUOX2 mRNA levels are elevated up to 20 times in active Crohn's ileitis and ulcerative colitis (Hamm et al., 2010; Haberman et al., 2014; Li et al., 2010; Malhotra et al., 2008; MacFie et al., 2014; Yanai et al., 2015). The gene discussed is CYBB; the disease is inflammatory bowel disease.