Possible enhancer activity of the conserved sequences in the far upstream HL regulatory region. HepG2 cells were transiently transfected with the indicated promoter-reporter constructs. At 48 h post-transfection, transcriptional activity was determined as the firefly over renilla luciferase activity. Data are expressed as percentage of the ratio measured in the hHL-685luc – transfected cells. Data are means ± SD from 3–4 independent experiments, each performed in quadruplicate. *and **: P < 0.05; and P < 0.01, respectively.