Increased transcription of MAO-B upon infection by Simian immunodeficiency virus [35] and stimulation of 5-HT release from the host cells by Rotavirus [36] and DV [37] have been shown; moreover, elevation of NE and EPI plasma levels in patients with neurological complications after Enterovirus 71 (EV71) infection with a parallel enhancement of virus titers and infectivity in human leukocyte cell lines by the two catecholamines [38] has been observed. The gene discussed is MAOB; the disease is infection.