The tumor microenvironment consists of various cells (such as macrophages, neutrophils, dendritic cells, bone marrow-derived suppressor cells, NK cells, T cells, B cells, tumor-associated fibroblasts) and abundant extracellular matrix (such as collagen, fibronectin, laminin, proteoglycans), as well as various cytokines (such as IL-1β, IL-6, IFN-γ, TGF-β) (47–49). Here, IL6 is linked to neoplasm.