STAT3 and cancer: Previous studies have suggested that inflammatory mediator and transcription factors including ILs, CKs, tumor necrosis factor-α (TNF-α), transforming growth factor-β (TGF-β), and granulocyte macrophage colony-stimulating factor (GM-CSF), as well as nuclear factor kB (NF-kB), signal transducer and activator of transcription 3 (STAT3) are essential for cancer-related inflammation (13).