The following DataNodes have no identifier: 2
http://classic.wikipathways.org/instance/WP1486_r126275 http://rdf.wikipathways.org/Pathway/WP1486_r126275/DataNode/d5510 (Cl -)
http://classic.wikipathways.org/instance/WP1486_r126275 http://rdf.wikipathways.org/Pathway/WP1486_r126275/DataNode/f741d (SYN6)
More details at https://www.wikipathways.org/WikiPathwaysCurator/DataNodesTests/dataNodesWithoutIdentifier