The following genes with an identifier have been found but that do not have a mapping to Ensembl: 3
http://classic.wikipathways.org/instance/WP830_r118407 POLR2K with datasource Entrez Gene
http://classic.wikipathways.org/instance/WP830_r118407 TAF6 with datasource Entrez Gene
http://classic.wikipathways.org/instance/WP830_r118407 POLR1B with datasource Entrez Gene
More details at https://www.wikipathways.org/WikiPathwaysCurator/GeneTests/genesWithoutEnsemblMapping