To identify oestrogen-regulated lncRNAs in breast cancer cells, we treated ERα-positive MCF-7 cells with E2 or with vehicle, and measured lncRNA expression using our custom microarrays, which detect transcripts from more than 6000 lncRNA genes that had been catalogued from full-length GenBank cDNA sequences without any conservation-based filtering [19]. Here, ESR1 is linked to breast carcinoma.