The following DataNodes have no identifier: 1
http://classic.wikipathways.org/instance/WP4756_r127761 http://rdf.wikipathways.org/Pathway/WP4756_r127761/DataNode/e9b04 (AGTR1 Inhibitor)
More details at https://www.wikipathways.org/WikiPathwaysCurator/DataNodesTests/dataNodesWithoutIdentifier