Few studies have examined the effect of Nox2 deficiency on the expression of adhesion molecules in humans; however, consistent with our findings, studies in patients with chronic granulomatous disease (a genetic disorder characterized by defective NADPH oxidase activity) and colitis demonstrated increased colonic ICAM-1 expression compared with patients without chronic granulomatous disease (24). This evidence concerns the gene FMO5 and chronic granulomatous disease.