The following genes with an identifier have been found but that do not have a mapping to Ensembl: 4
http://classic.wikipathways.org/instance/WP161_r137232 Tbxa2r with datasource Entrez Gene
http://classic.wikipathways.org/instance/WP161_r137232 S1pr4 with datasource Entrez Gene
http://classic.wikipathways.org/instance/WP161_r137232 Mtnr1b with datasource Entrez Gene
http://classic.wikipathways.org/instance/WP161_r137232 S1pr2 with datasource Entrez Gene
More details at https://www.wikipathways.org/WikiPathwaysCurator/GeneTests/genesWithoutEnsemblMapping