HMOX1 and hepatocellular carcinoma: Furthermore, we confirmed that HO-1 depletion decreased the phosphorylation of STAT3 in overexpressing 14–3-3ζ HCC cells, compared to cells overexpressing 14–3-3ζ alone (Fig. 5h), demonstrating a significant role of HO-1 in 14–3-3ζ-mediated STAT3 signaling activation.