The following DataNodes have no identifier: 2
http://classic.wikipathways.org/instance/WP3901_r116991 http://rdf.wikipathways.org/Pathway/WP3901_r116991/DataNode/daf84 (DAG)
http://classic.wikipathways.org/instance/WP3901_r116991 http://rdf.wikipathways.org/Pathway/WP3901_r116991/DataNode/f760a (LysoPhosphatidic
Acid)
More details at https://www.wikipathways.org/WikiPathwaysCurator/DataNodesTests/dataNodesWithoutIdentifier