USF2 and hepatocellular carcinoma: USF2 repressed PAI-1 expression in primary rat hepatocytes (Samoylenko et al., 2001); likewise USF2 mediated suppression of PAI-1 expression in response to the polyphenol quercetin in human endothelial cells (Olave et al., 2010); however, it induced PAI-1 expression in human and in rat hepatoma cell lines, indicating that the effect of USF2 on PAI-1 expression is cell-type specific (Dimova and Kietzmann, 2006).