Orthology Ontology	Drug Target Ontology	Source
http://purl.obolibrary.org/obo/CDAO_0000140	http://purl.obolibrary.org/obo/BTO_0001156	LOOM
http://purl.org/net/orth#Gene	http://www.drugtargetontology.org/dto/DTO_00200000	LOOM
http://purl.obolibrary.org/obo/SO_0000704	http://www.drugtargetontology.org/dto/DTO_00200000	LOOM
http://purl.org/net/orth#Protein	http://purl.obolibrary.org/obo/PR_000000001	LOOM