Luciferase activity on human 293 cells transfected with different plasmids of pRL or pGL3 under the control of different promoters, including vector, CMV, and sEH promoters, respectively, in the absence and presence of 17β-E2 (E2, 10 nM) or E2 pus ICI 182,780 (ICI, 100 nM). *Significant difference from transfection with sEH promoter (0.4 kb) alone, and from the 0.4-kb sEH promoter plus E2 and ICI, respectively (n = 3–6).