NADPH oxidases (Nox) are the major sources of ROS production in the myocardium in conditions such as myocardial infarction, HF and aging, and are therefore important contributors to the oxidative stress, cytokine release and cardiac dysfunction that underlie adverse myocardial remodeling (Kuroda et al., 2010; Ago et al., 2010). This evidence concerns the gene FMO5 and hydrops fetalis.