This is a collaborative effort undertaken by Fraunhofer SCAI group(Stepan Gebel, Alpha Tom Kodamullil, Sumit Madan, Johannes Darms), University of Michigan(Yongqun "Oliver" He), NIH PubChem (Qingliang "Leon" Li), and NIH/NHGRI (Asiyah Lin) to develop an ontology to represent clinical trials using a small set of core terms.
The CTO-core uses Basic Formal Ontology (BFO) as its top level ontology.
OPMI led by University of Michigan and other OBO foundry ontologies serve as the pool of existing terms to import into CTO core.