STAT3 and hepatocellular carcinoma: As IL-6 represents a crucial HCC-promoting pro-inflammatory cytokine in obese state7,9, we treated both HepG2 and Huh7 HCC cell lines with IL-6, and found increased phosphorylation of STAT3 at Tyr705 (p-STAT3Tyr705) and elevated mRNA and protein expressions of CCRK, which were abrogated by short-interfering RNA (siRNA)-mediated knockdown of STAT3 (Fig. 3a, b).