We performed a luciferase reporter assay using previously defined sections of the PTEN promoter/regulatory region that contain transcriptionally active chromatin elements in various non-tumorigenic breast cell lines and tissue (separated by compartment) as well as in breast cancer cell lines (Supplementary Fig. 2) fused to a luciferase reporter gene (Fig. 2a)23. The gene discussed is PTEN; the disease is breast carcinoma.