In GBM patients, the hostile tumor microenvironment comprises, amongst other factors, interleukin (IL)-10, transforming growth factor-beta (TGF-β), and indoleamine 2,3-dioxygenase (IDO), which potently suppress the function of DC.6,8 Furthermore, this patient group is often treated with corticosteroids, mainly dexamethasone (Dex), to control cerebral edema. The gene discussed is IL10; the disease is neoplasm.