M2 type microglia/macrophage also inhibits the function of Teff cell and promotes the progression of GBM by secreting cytokines such as interleukin-6 (IL-6), interleukin-10 (IL-10) and C–C Motif Chemokine Ligand 2 (CCL2) [16]. Here, IL6 is linked to glioblastoma.