In the vasculature of humans and experimental animals with SCD, reactive oxygen species (ROS)-generated enzymes NADPH oxidase (NOX) and xanthine oxidase, endothelial NO synthase (eNOS) uncoupling, autooxidation of HbS, heme iron release, and increased asymmetric dimethylarginine have been described (28, 29). The gene discussed is FMO5; the disease is Schnyder corneal dystrophy.