The following DataNodes have no identifier: 2
http://classic.wikipathways.org/instance/WP1765_r126405 http://rdf.wikipathways.org/Pathway/WP1765_r126405/DataNode/b6002 (Harsh tail touch)
http://classic.wikipathways.org/instance/WP1765_r126405 http://rdf.wikipathways.org/Pathway/WP1765_r126405/DataNode/e631e (Pumping)
More details at https://www.wikipathways.org/WikiPathwaysCurator/DataNodesTests/dataNodesWithoutIdentifier