In vitro and preclinical studies have shown promising results for cell therapies [61,62,63,64], but these findings have not been entirely satisfactory partially due to the immunosuppressive tumor microenvironment: thus, new GBM-targeting CAR-T cells countering TGF-β-mediated immune suppression in the TME are being developed on murine models [65]. This evidence concerns the gene TGFB1 and glioblastoma.