The parallel observation of increased ROS products in Iba-1 positive microglia/macrophages and upregulation of NADPH oxidase on the transcriptome level indicates ROS production by microglia/macrophages as a pivotal factor in the pathogenesis of CDV-induced demyelinating CNS disease and thus also substantiates CDV-DL as a naturally occurring animal model for human demyelinating disease such as MS. The gene discussed is FMO5; the disease is demyelinating disease.