STAT3 and hepatocellular carcinoma: Quantitative PCR and flow cytometry analyses showed that treatment with HCC-CAFs CM in the presence of S31 reversed the enhancement of IL-8, TNFa, and CCL2 mRNA levels and CD66b and PDL1 protein levels in neutrophils (Fig. 3e, f), suggesting that the activation of neutrophils by HCC-CAFs CM is dependent on the JAK-STAT3 signaling pathway.