IGFBP1 and hepatocellular carcinoma: Because insulin-like growth factor-binding protein gene (IGFBP-1) promoter regulates blood glucose levels, the specific upregulation of IGFBP-1 mRNA in human hepatocytes and HepG2 human hepatoma cells, even in the presence of insulin, might account for the disruptive effects of TCDD on glucose metabolism [112].