Recently, it was shown that atrial overexpression of gp91phox-containing NAPDH oxidases (NOX2), the activity of which is upregulated in the atria in AF and represents the predominant sources of atrial O2•−, does not contribute to atrial electrical or structural remodeling parameters in mice and has modest effects on AF inducibility but no effect on AF duration[70,71]. Here, FMO5 is linked to atrial fibrillation.