The following DataNodes have no identifier: 1
http://classic.wikipathways.org/instance/WP1218_r106097 http://rdf.wikipathways.org/Pathway/WP1218_r106097/DataNode/c43b6 (ALR2)
More details at https://www.wikipathways.org/WikiPathwaysCurator/DataNodesTests/dataNodesWithoutIdentifier