http://www.ebi.ac.uk/efo/EFO_0001440

A role is an entity which is borne in a material entity in some kinds of natural, social or institutional contexts, but which is not essential to the fundamental definition of that material entity (i.e. the material entity exists with or without the role). For example, the role of a person as a surgeon, the role of an artificial heart in pumping blood, the role of a chemical compound in an experiment, the role of a drug in the treatment of a disease.

For example, the role of a person as a surgeon, the role of an artificial heart in pumping blood, the role of a chemical compound in an experiment, the role of a drug in the treatment of a disease.

http://www.ifomis.org/bfo/1.1/snap#Role

true

A realizable entity [snap:RealizableEntity] the manifestation of which brings about some result or end that is not essential to a continuant [snap:Continuant] in virtue of the kind of thing that it is but that can be served or participated in by that kind of continuant [snap:Continuant] in some kinds of natural, social or institutional contexts.

James Malone