Representing experimental variables with EFO
The Experimental Factor Ontology (EFO) is developed by the EMBL-EBI Samples, Phenotypes and Ontologies Team (SPOT). Its scope is to support the annotation, analysis and visualization of data handled by many groups at the EBI, and to serve as the core ontology for Open Targets. We also add terms for external users when requested.
New to ontologies? Read a blog post by James Malone on what ontologies are for, or see our FAQ.
Browse
Browse and search EFO with EMBL-EBI's Ontology Lookup Service (OLS4) or the NCBO BioPortal. The EFO source ontology is on GitHub.
Submit a Term
Submit new terms or report issues via our GitHub issue tracker, or email efo-users@ebi.ac.uk. For monthly release announcements, join the efo-users mailing list.
Download
Download the latest EFO release in OWL format or the OBO format version. Read the Release Notes. Previous releases are also available, e.g. v3.14.0.
FAQ
Read about EFO or see the Frequently Asked Questions for information on EFO's structure, how it's updated, how to cite it, and more.
Tools
We provide tools supporting EFO development and use, including OxO (ontology cross-referencing), Zooma (annotation mapping), and OntoString.
Contact
Email the EFO user list with any questions or comments. EFO is released under the Apache 2.0 license, subject to EMBL-EBI's Terms of Use.