The following DataNodes have no identifier: 2
http://classic.wikipathways.org/instance/WP2904_r117927 http://rdf.wikipathways.org/Pathway/WP2904_r117927/DataNode/be7bc (Cell proliferation and survival)
http://classic.wikipathways.org/instance/WP2904_r117927 http://rdf.wikipathways.org/Pathway/WP2904_r117927/DataNode/ae739 (Hippo pathway)
More details at https://www.wikipathways.org/WikiPathwaysCurator/DataNodesTests/dataNodesWithoutIdentifier