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 breast mucinous carcinoma that is characterized by both intracellular and extracellular mucin and cystic spaces are lined by tall columnar cells that contain profuse extracellular mucin. (DO)