> For the complete documentation index, see [llms.txt](https://platform-docs.opentargets.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://platform-docs.opentargets.org/disease-or-phenotype.md).

# Disease or Phenotype

## Overview

A disease or phenotype in the Platform is understood as any disease, phenotype, biological process or measurement that might have any type of causality relationship with a human target. The EMBL-EBI [Experimental Factor Ontology](https://www.ebi.ac.uk/efo/) (EFO) is used as scaffold for the disease or phenotype entity.

In order to maximise the alignment of the ontology with a clinical application, a few modifications have been added to EFO. Some high-level terms have been removed (e.g. disease by anatomical region) and others have been rearranged to align them to a less anatomical and more clinical interpretation. For each EFO release, the EFO OTAR slim can be found in parallel with the official [EFO release](https://github.com/EBISPOT/efo/releases).

{% embed url="<https://www.youtube.com/watch?v=jUc_Dpm1hJ0>" %}

## Disease or phenotype annotation data sources

| Annotation data                                                                     | Data source                                                                      |
| ----------------------------------------------------------------------------------- | -------------------------------------------------------------------------------- |
| Description; cross-references; synonyms; location; ontology and classification      | [EFO](https://www.ebi.ac.uk/efo/)                                                |
| [Drugs and Clinical Candidates](/disease-or-phenotype/drugs.md)                     | [Open Targets](https://github.com/opentargets/clinical_mining)                   |
| [Clinical signs and symptoms](/disease-or-phenotype/clinical-signs-and-symptoms.md) | [HPO](https://hpo.jax.org/app/) and [MONDO](https://mondo.monarchinitiative.org) |
| [Bibliography](/bibliography.md)                                                    | [Open Targets](/bibliography.md)                                                 |