Considering the view that both NOX4 and NOX5 appear to play roles in DKD, we examined the pathogenic role of NOX5 in the presence or absence of NOX4 expression using endothelial cell (EC)-specific NOX5 transgenic mice in a streptozotocin (STZ)-induced insulin-deficient type 1 diabetes model. This evidence concerns the gene NOX5 and type 1 diabetes mellitus.