NOX5 and gastroesophageal reflux disease: ROS synthesis by NADPH oxidase NOX5 and SOD2 has been suggested to contribute to progression of gastroesophageal reflux disease, which characteristically exposes the esophageal tissue to acids causing increased intracellular Ca2+-ROCK2 signaling and upregulation of NOX5 mRNA synthesis, to esophageal adenocarcinoma (139).