KLRK1 and glioblastoma: To assess the cytotoxicity of NKG2D CAR-T cells against glioblastoma cells, we incubated CAR-T and untransduced control T (UTD) cells with target cells (U251, U87, and A172) at various E: T ratios (10:1, 5:1, 2.5:1, and 1.25:1).