IL6 and neoplasm: Soluble factors secreted by tumor cells, like transforming growth factor-β (TGFβ), IL-6, platelet-derived growth factor (PDGF), epidermal growth factor (EGF), VEGF, and stromal cell-derived factor 1 (SDF1; also known as CXCL12), serve as important signaling molecules as they bind to receptors located on target cells [11].