title: Region Evolution eXplorer - A tool for discovering evolution trends in ontology regions.
abstract: BACKGROUND
  A large number of life science ontologies has been developed to support different application scenarios such as gene annotation or functional analysis. The continuous accumulation of new insights and knowledge affects specific portions in ontologies and thus leads to their adaptation. Therefore, it is valuable to study which ontology parts have been extensively modified or remained unchanged. Users can monitor the evolution of an ontology to improve its further development or apply the knowledge in their applications.
  
  
  RESULTS
  Here we present REX (Region Evolution eXplorer) a web-based system for exploring the evolution of ontology parts (regions). REX provides an analysis platform for currently about 1,000 versions of 16 well-known life science ontologies. Interactive workflows allow an explorative analysis of changing ontology regions and can be used to study evolution trends for long-term periods.
  
  
  CONCLUSIONS
  REX is a web application providing an interactive and user-friendly interface to identify (un)stable regions in large life science ontologies. It is available at http://www.izbi.de/rex.
authors.affiliation: Department of Computer Science, Universität Leipzig, Augustusplatz 10, Leipzig, Germany.
authors.forename: Victor
authors.initials: V
authors.lastname: Christen
authors.affiliation: Department of Computer Science, Universität Leipzig, Augustusplatz 10, Leipzig, Germany ; Interdisciplinary Center for Bioinformatics, Universität Leipzig, Härtelstr. 16 - 18, Leipzig, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Hartung
authors.affiliation: Department of Computer Science, Universität Leipzig, Augustusplatz 10, Leipzig, Germany ; Interdisciplinary Center for Bioinformatics, Universität Leipzig, Härtelstr. 16 - 18, Leipzig, Germany.
authors.forename: Anika
authors.initials: A
authors.lastname: Groß
keywords: Ontologies; Ontology evolution; Ontology visualization