In summary, we show that Hsp70 in the circulation and on the membrane of tumor cells, in the presence of IL-2, stimulates NK cells in patients with grade 3 glioma and possibly confers a survival benefit to these patients, whereas in patients with grade 4 GBM with low CD4+ helper T cells, the NK cell stimulation is hindered. The gene discussed is IL2; the disease is glioblastoma.