The following DataNodes have no identifier: 2
http://classic.wikipathways.org/instance/WP2224_r118113 http://rdf.wikipathways.org/Pathway/WP2224_r118113/DataNode/dd7a5 (Short chain ascarosides)
http://classic.wikipathways.org/instance/WP2224_r118113 http://rdf.wikipathways.org/Pathway/WP2224_r118113/DataNode/ef5eb (very long chain fatty acids (VLCFAs))
More details at https://www.wikipathways.org/WikiPathwaysCurator/DataNodesTests/dataNodesWithoutIdentifier