The Cell Ontology is an ontology that aims at capturing the diversity of cell types in animals.
[1] It is part of the Open Biomedical and Biological Ontologies (OBO) Foundry.
[2] The Cell Ontology identifiers and organizational structure are used to annotate data at the level of cell types, for example in single-cell RNA-seq studies.
[3] It is one important resource in the construction of the Human Cell Atlas.
[4] The Cell Ontology was first described in an academic article in 2005.