Catalase-positive bacteria and fungi such as staphylococci, Serratia, Burkholderia, and Aspergillus are particularly important pathogens in patients with CGD, because they express some catalase and thus can neutralize the small amounts of hydrogen peroxide that phagocytes produce by mechanisms other than NADPH oxidase.3,4,10–12. The gene discussed is FMO5; the disease is chronic granulomatous disease.