Further studies, however, are certainly required for the clinical approval of such therapeutic approach either in GBM or MNG, as not only CD8+ cytotoxic T cells and NK cells respond with clonal expansion to an IL-2/IL-15 cocktail, but the dominantly present immunosuppressive T cells as well, which might explain the variable success of such therapeutic attempts so far [53]. Here, CD8A is linked to glioblastoma.