the immune system to recruit white blood cells for the healing process. A study in Nature suggested that asthma sufferers have higher levels of hydrogen peroxide in their lungs than healthy people, which would explain why these patients also have inappropriate levels of white blood cells in their lungs. Asthma sufferers might have certain variations in cellular levels of NAD+/NADP+ or FAD, which causes malate oxidase to shift to oxygen as its oxidant, due to its high abundancy in the lungs. This could be a possible explanation for the elevated levels of hydrogen peroxide in their lungs. Uses Topical compositions of malate oxidase combined with suitable disease-detecting biomarkers and a chemiluminescent dye are used in disease detecting systems. The biomarker activates the malate oxidase to generate hydrogen peroxide that excites the light-emitting dye, which exhibits chemiluminescence in the presence of the peroxide. Such contemporary compositions are thus used as a diagnostic tool for detecting diseases. In a similar method, malate oxidase is used in the transcutaneous measurement of the amount of a substrate in blood. The method is conducted by contacting the skin with the enzyme, reacting the substrate with the enzyme and directly detecting the amount of H2O2 produced as a measure of the amount of substrate in the blood, with use of a hydrogen peroxide electrode. Further dermatological applications are in drugs or cosmetic agents, comprising a suitable substrate and malate oxidase as hydrogen peroxide producing enzyme for skin lightening and age spots or freckles. Other illustrative uses that employ the capacity of malate oxidase to yield hydrogen peroxide in the presence of a suitable substrate, including malate, are found in toothpaste to remove bacterial plaque, cleaning compositions for removing blood stains and the like, and in the removal of chewing gum lumps stuck on surfaces by enzymatic degradation. Malate oxidase is also employed in the inhibition of corrosion by dissolved oxygen in water by converting it to hydrogen peroxide, which is subsequently broken down into water and oxygen by catalase. References EC 1.1.3 Flavoproteins Enzymes of unknown structure