# External Ontologies
## General Data Transformations
Ontologies are structured data writing in RDF/XML syntax or in OWL. They are great resources to express very complex and precise domain-specific knowledge. In practice, they aren't that useful by itself because:
* Not human readable, and you'll need special software like Protege
* T-box structured
* Good for schemas, bad for analysis
For more information about the different ontologies in the biomedical space, we recommend checking out the documentation on [obo foundry](https://obofoundry.org/).
For practical reasons we transform ontologies from their T-Box structures into A-Box schemas. In other words, we map a "Class" in an ontology as an Object in the data graph itself.
T-Box pattern for diseases
Inside our labelled property graph, we can use labels to denote the Conceptual hierarchies of your core ontology.
