Result: Both STAT1 and STAT3 proteins were expressed in HCC cells, and when STAT1 levels decreased, there was strongly phosphorylation of STAT3 Tyr 705 (pSTAT3 Tyr705) after 2 h of IFN - exposure but not long. When STAT3 levels decreased, IL-6 induced prolonged STAT1 signaling and interplay of STAT1 and STAT3 signaling in the presence of proinflammatory IL-6.