Haifeng Zhang, et al. - The function of the mitochondrial antioxidant system thioredoxin (Trx2) in vasculature is not understood. By using endothelial cell (EC)-specific transgenesis of the mitochondrial form of the thioredoxin gene in mice (Trx2 TG), we show the critical roles of Trx2 in regulating endothelium functions