FMO5 and Hyperglycemia: Diabetic IRS2−/− mice are hyperglycaemic (Withers et al., 1998, 1999; González-Rodríguez et al., 2010; Burgos-Ramos et al., 2012) and hyperglycaemia itself activates NADPH oxidases to accelerate oxidative stress (Koike et al., 2007), which is considered an important mediator of diabetic complications (Inoguchi et al., 2007).