To study the regulation of the glucose-6-phosphatase promoter/luciferase reporter genes by C2/CREB, we decided to use the human hepatoma cell line HepG2, as it has been reported that activation of the cAMP signaling pathway stimulates glucose-6-phosphatase gene transcription in these cells [17,21,22]. This evidence concerns the gene CREB1 and hepatocellular carcinoma.