Malate dehydrogenase 1 (MDH1), which was decreased in MS/CIS patients relative to controls, oxidizes the reduced form of nicotinamide adenine dinucleotide (NADH) to its oxidised form (NAD +) in the cytosol, making NAD+ available for the citric acid cycle in the mitochondria77. This evidence concerns the gene MDH1 and in situ carcinoma.