IL6 and neoplasm: The current understanding of tumor-mediated immunosuppression in patients with glioblastoma shows that tumor cells suppress lymphocyte proliferation and interleukin-6 (IL-6) production via secreting prostaglandin E2 (PGE2) and transforming growth factor-β2 (TGF- β2) (Parney, 2012; Rolle et al., 2012).