IL6 and neoplasm: In tumor cells per se, hyperactivated STAT3 decreases the expression of immune-stimulating factors including interferons (IFNs), pro-inflammatory cytokines (IL-12, TNF-α) and chemokines (CCL5, CXCL10), while increases the expression of certain cytokines and growth factors (IL-6, IL-10, TGFβ, and VEGF), thereby exerting profound immune effects (Fig. 1b) [53].