For instance, focal irradiation improved the survival of GBM-tumor bearing mice treated with anti-PD-1 (118, 119), anti-CTLA-4 + 4-1BB activation (120), dual TIM-3 and PD-1 blockade (121) and anti-GITR (glucocorticoid-induced TNFR family related gene) (122). Here, CTLA4 is linked to glioblastoma.