The following genes with an identifier have been found but that do not have a mapping to Ensembl: 13
http://classic.wikipathways.org/instance/WP278_r137001 Timp1 with datasource Entrez Gene
http://classic.wikipathways.org/instance/WP278_r137001 Mmp8 with datasource Entrez Gene
http://classic.wikipathways.org/instance/WP278_r137001 Mmp7 with datasource Entrez Gene
http://classic.wikipathways.org/instance/WP278_r137001 Mmp1a with datasource Entrez Gene
http://classic.wikipathways.org/instance/WP278_r137001 Tcf20 with datasource Entrez Gene
http://classic.wikipathways.org/instance/WP278_r137001 Mmp12 with datasource Entrez Gene
http://classic.wikipathways.org/instance/WP278_r137001 Mmp10 with datasource Entrez Gene
http://classic.wikipathways.org/instance/WP278_r137001 Mmp13 with datasource Entrez Gene
http://classic.wikipathways.org/instance/WP278_r137001 Mmp20 with datasource Entrez Gene
http://classic.wikipathways.org/instance/WP278_r137001 Mmp27 with datasource Entrez Gene
http://classic.wikipathways.org/instance/WP278_r137001 Mmp19 with datasource Entrez Gene
http://classic.wikipathways.org/instance/WP278_r137001 Timp3 with datasource Entrez Gene
http://classic.wikipathways.org/instance/WP278_r137001 Mmp3 with datasource Entrez Gene
More details at https://www.wikipathways.org/WikiPathwaysCurator/GeneTests/genesWithoutEnsemblMapping