IL6 and hepatocellular carcinoma: Consistently, GNAS overexpression significantly promoted IL-6 mRNA expression in HCC cells, whereas treatment with pyrrolidine dithiocarbamate (PDTC), a specific NF-κB inhibitor, only slightly decreased the IL-6 mRNA expression, but did not completely suppress GNAS overexpression-induced IL-6 mRNA expression in HCC cells (Fig. 3b).