To this regard, literature reported some data on the possible link existing between peripheral side effects of this medication (such as erectile dysfunctions, pulmonary hypertension, platelet hyperaggregability and agranulocytosis) and increased NADPH oxidase-derived ROS production.49, 50, 51 To the best of our knowledge, no data are actually available describing a possible increase in NOX-derived brain oxidative stress because of this medication. The gene discussed is FMO5; the disease is pulmonary arterial hypertension.