ESR1 and breast carcinoma: To determine their transcriptomic effects on breast cancer cell gene expression and to identify potential target mechanisms of LXR ligands, we performed microarray analysis of gene expression in MCF-7, T-47D, SK-BR-3, or MDA-MB-231 cells, four well-characterized cell line models of ER+ and ER- breast cancers, which express both LXRα and LXRβ (Additional file 2) and have previously been shown to be sensitive to LXR ligand treatment [20], following either control treatments with dimethyl sulfoxide (DMSO) vehicle or GW3965 LXR ligand.