STAT3 and cancer: In the pathogenesis of cancer, increased IL-6 directly on stimulate cells in the TME to upregulate STAT3 target genes, subsequently driving the expression of proliferation-promoting proteins (such as cyclin D1), survival-associated molecules (such as BCL2-like protein 1), angiogenic factors (such as VEGF), invasiveness and metastasis-related proteins (such as matrix metalloproteinases) and immunosuppressive molecules (such as IL-10 and TGF-β) (Johnson et al., 2018).