treatment upregulates Rora promoter activity. HepG2 cells cultured in 12-well plates were co-transfected with 500 ng/well of the pTRα vector, allowing expression of the TR, and 500 ng/well of the p(-487)Rora-Luc reporter vector, which allows expression of the luciferase gene under the control of the human genomic sequences between nucleotides -487 and -45 from the Rora1 translation initiation site, or with 500 ng/well of the promoter-less pGL3-Luc vector. HepG2 cells co-transfected with 500 ng/well of the pTRα vector and of the pDR4-TK-Luc reporter vector were used as a control of the transcriptional effect of T3 on a TH response element. The luciferase activity of p(-487)Rora-Luc and pDR4-Luc in the absence or the presence of T3 (30 nM) is expressed relative to that of the promoter-less pGL3-Luc vector (*P < 0.05). Error bars indicate mean ± standard deviation.