IL6 and neoplasm: Fibroblasts become excessively active in a tumor microenvironment, and support breast tumor growth through versatile functions of many secretory proteins, cytokines, and transcriptional factors, for example, MMPs, VEGF, TGF-β, PDGF, IL-6, EGF, IGF, IGF, FGF, CTGF, PGE2, CXCLs, CCRs, CCLs, TNF, INF-γ, and NF-kB, etc. (Figure 3) [60,61,62,63,64,65].