IL6 and neoplasm: Tumor cells, MDSCs, and tumor-associated cells, such as tumor-associated fibroblasts (TAFs) and endothelial cells (83), can contribute to tissue modifications of the ECM by matrix metalloproteases (MMPs) and fibroblast activation proteins and the release of soluble factors (basic fibroblast growth factor [FGF], platelet-derived growth factor, hepatocyte growth factor, insulin-like growth factor), chemokines (CCL2, SDF1a/CXCL12, CXCL8), and immunosuppressive cytokines, such as transforming growth factor beta (TGF-β), IL-10, and IL-6 (84, 85).