The following DataNodes have no identifier: 1
http://classic.wikipathways.org/instance/WP4860_r124635 http://rdf.wikipathways.org/Pathway/WP4860_r124635/DataNode/d1f64 (Substrate)
More details at https://www.wikipathways.org/WikiPathwaysCurator/DataNodesTests/dataNodesWithoutIdentifier