The following DataNodes have no identifier: 1
http://classic.wikipathways.org/instance/WP2074_r117928 http://rdf.wikipathways.org/Pathway/WP2074_r117928/DataNode/ce0a4 (Differentiation)
More details at https://www.wikipathways.org/WikiPathwaysCurator/DataNodesTests/dataNodesWithoutIdentifier