ESR1 and breast neoplasm: [One methylation signature gene, LRCC26, was not represented on the Affymetrix and was not included in our analysis.] This geneset was then used to carry out geneset enrichment analysis (GSEA) of an open source dataset derived from Affymetrix microarray analysis of 76 ER+ and 53 ER− primary breast tumors [8] (GEO accession number: GSE5460).