IL6 and neoplasm: On the other hand, M2 phenotype macrophages are educated to be tumor-promoting by releasing growth factors like PDGF, TGFβ1, HGF, and bFGF et al. [4, 39], forming a positive feed-back loop in accordance with cytokines and factors of tumor cells (IL-4, IL-6, IL-10, MDF, TGFβ1, PGE2, et al.)[40] (Fig. 2b).