The following genes with an identifier have been found but that do not have a mapping to Ensembl: 3
http://classic.wikipathways.org/instance/WP517_r116994 APH1B with datasource Entrez Gene
http://classic.wikipathways.org/instance/WP517_r116994 Kcnj5 with datasource Entrez Gene
http://classic.wikipathways.org/instance/WP517_r116994 PTCRA with datasource Entrez Gene
More details at https://www.wikipathways.org/WikiPathwaysCurator/GeneTests/genesWithoutEnsemblMapping