RGD uses the Human Disease Ontology (DO, https://disease-ontology.org/) for disease curation across species. RGD automatically downloads each new release of the ontology on a monthly basis. Some additional terms which are required for RGD's curation purposes but are not currently covered in the official version of DO have been added. As corresponding terms are added to DO, these custom terms are retired and the DO terms substituted in existing annotations and subsequently used for curation.
A pre-malignant neoplasm that is characterized by abnormal growth of dysplastic squamous epithelial cells on the surface of the eye that arises from the conjunctiva that is restricted within the epithelium. (DO)