- *HOG.obo* and *vHOG.obo* ontologies are not maintained anymore, they are
  integrated in Uberon.
- *organ_association_HOG.txt* and *organ_association_vHOG.txt* are not
  maintained anymore.
- *stage_association.txt* is not maintained anymore.
Archived files can be found in ftp://ftp.bgee.org/general/ontologies/


- *stages.obo* can be found at
  https://github.com/obophenotype/developmental-stage-ontologies/blob/master/external/bgee/dev_stage_ontology.obo