Databases, such as Ontology Lookup Service or ses, such as MIRIAM Registry or of the EBI-EMBL, the TissueDistributionDB, including the Tissue Synonym Library of the German Cancer Research Center (DKFZ) in Heidelberg or the Bioportal platform of the National Center for Biomedical Ontology in Stanford, USA rely on BTO and implement the encyclopedia as an essential repository of information into their respective platform.

BTO enables users from medical research and pharmaceutical sciences to search for the occurrence and histological detection of disease-related enzymes in tissues, which play an important role in diagnosis, therapies, and drug development.

In biochemistry and biotechnology the organism-specific tissue terms linked to enzyme functional data are an important resource for the understanding of the metabolism and regulation in life sciences.

Development of BTO started in 2003, aimed to connect the biochemical and molecular biological enzyme data of BRENDA with a hierarchical and standardized collection of tissue-specific terms.

The functional enzyme data and information in BRENDA have been manually annotated and structured by experts from biochemistry, biology, and chemistry.

The terms are classified under generic categories, rules, and formats of the Gene Ontology Consortium (GO,[3]), organized as a directed acyclic graph (DAG) created using the open-source OBO-Edit.

The result page displays all enzymes which are isolated or detected in the searched tissue term, directly linked to BTO.