Bioinformatics manages the information that has been gathered in databases since the advent of the molecular biology technological revolution. The successful research is based in interpretations of that information that can be accessed and managed computationally, which is a difficult task. An attempt to solve that problem is to use ontologies. Ontologies are computational formalisations of the knowledge about a given domain, allowing computers to manage the information in a semantic level. In medical informatics, ontologies have been used for a longer period of time to produce controlled lexicons for coding schemes. Bio-ontologies define the basic terms and relations in biological domains and are being used among others, as community refere...