The following DataNodes have no identifier: 1
http://classic.wikipathways.org/instance/WP3134_r117551 http://rdf.wikipathways.org/Pathway/WP3134_r117551/DataNode/fc7a3 (PKA)
More details at https://www.wikipathways.org/WikiPathwaysCurator/DataNodesTests/dataNodesWithoutIdentifier