. _:vb50955572 . . "DOID:7994"^^ . . _:vb50955572 . _:vb50955572 . . "disease_ontology"^^ . _:vb50955572 . _:vb50955572 . "NCI:C7002"^^ . "central nervous system osteosarcoma"^^ . "UMLS_CUI:C1335150"^^ .