As eNOS has an important role in maintaining the cerebral blood flow,6 the decreased eNOS protein level may, to some extent, contribute to the reported cerebral blood flow reduction in the frontal cortex in schizophrenia.43, 44, 45 An earlier study reported decreased plasma arginase activity in patients with schizophrenia.9 The present study, interestingly, found an over 50% increase in arginase activity in BA8 accompanied by a significant upregulation of arginase II in the schizophrenia group. The gene discussed is NOS3; the disease is schizophrenia.