An orphan virus is a virus that is not associated with a disease but may possess pathogenicity. Some orphan viruses include adeno-associated virus (Parvoviridae), human herpesvirus 7 (Herpesviridae), human foamy virus (Retroviridae), Human Reovirus (Reoviridae), hepatitis G (Flaviviridae), and TT virus (Anelloviridae). Gilbert Dalldorf, a pathologist who showed that Coxsackie viruses paralyze mice but not humans, indicated that the term ‘orphan’ was created "in a moment of conviviality" by a group of virologists.