In GBM’s microenvironment, different mediators are secreted by several cell subtypes, which constitute a complex network between immune and neoplastic compartments, such as: (i) cytokines (IL-6, IL-10, VEGF, TGFβ, M-CSF, GM-CSF, bFGF); (ii) prostaglandins (PGE2); (iii) chemokines (CCL20 and CXCL8); (iv) reactive oxygen species; and (v) cellular components like gangliosides [146,147,148]. The gene discussed is CCL20; the disease is glioblastoma.