The following genes with an identifier have been found but that do not have a mapping to Ensembl: 2
http://classic.wikipathways.org/instance/WP835_r137202 PPP2R1B with datasource Entrez Gene
http://classic.wikipathways.org/instance/WP835_r137202 GYS1 with datasource Entrez Gene
More details at https://www.wikipathways.org/WikiPathwaysCurator/GeneTests/genesWithoutEnsemblMapping