TGFB1 and medulloblastoma: Similar to what was observed in the presence of exogenous TGF-β (using the same cells), nontransduced NK cells have significantly decreased killing in the presence of medulloblastoma-conditioned media (21.21 ± 1.19% killing at E:T 5:1 in the absence vs. 14.98 ± 2.11% in the presence of medulloblastoma-conditioned media, n = 8, p = 0.02) and transduced (gray lines; 21.11 ± 1.84% killing at E:T 5:1 in the absence vs. 21.81 ± 3.37 in the presence of medulloblastoma-conditioned media, n = 8, p = 0.85; Fig. 3a).