STAT3 and hepatocellular carcinoma: He et al. reported that peritumoral neutrophils up-regulate Programmed cell death ligand-1 (PDL-1) expression and suppress T-cell proliferation in hepatocellular carcinoma [10, 11], while Wang et al. have reported that tumor-derived Granulocyte macrophage colony-stimulating factor (GM-CSF) activates neutrophils and induces neutrophil PD-L1 expression through the Janus kinase and signal transducer and activator of transcription 3 (JAK-STAT3) pathway [11].