Increased levels of TRegs have been found in the tumors and peripheral blood of patients with various malignancies including glioblastoma multiforme (GBM), and within GBM, we have shown TRegs to be an important and reversible component of the immunosuppression endemic to this disease [19]–[23].Early attempts to clinically deplete TRegs and alleviate anti-tumor immunosuppression targeted the high affinity interleukin-2 (IL-2) Receptor (IL-2Rα/CD25) due to its constitutive expression on the TReg population. Here, IL2RA is linked to glioblastoma.