NOS3 and schizophrenia: We suggest that oxidation and inflammation associated with schizophrenia can also contribute to uncoupling and reduced activity of endothelial eNOS (16) (Figure 1); ROS promotes oxidative conversion of the eNOS cofactor BH4 to dihydrobiopterin (BH2), thereby reducing endothelial BH4 bioavailability, which in turn inhibits eNOS activity (16).