These defects cause chronic granulomatous disease which are characterized by immunodeficiency and can cause IBD‐like intestinal inflammation.57 Inflammatory reactions in CGD patients (namely colitis) might be a result of impaired anti‐bacterial protection due to impaired NOX activity, resembling defects in ephithelial‐specific NADPH Oxidase 1 (NOX1) and Dual Oxidase 2 (DUOX2) in patients with severe EO‐IBD. Here, DUOX2 is linked to Immunodeficiency.