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 tertiary syphilis that is characterized by granulomatous lesions, called gummas, which are characterized by a center of necrotic tissue with a rubbery texture. They form in the liver, bones, and testes but may affect any organ. (DO)