To determine the role of E2F2 in breast cancer cell proliferation, we carried out RNA interference experiments in MCF-7 and T-47D (ER+) and MDA-MB-231 (ER-) cells and measured the effects of E2F2 knockdown, mimicking the effects of LXR ligand treatment, on cell numbers over a 72-hour period. This evidence concerns the gene E2F2 and breast carcinoma.