We pulsed medulloblastoma exosomes onto activated healthy donor PBMCs and found a dichotomy in the response of the PHA-activated T cells–relatively low doses of tumor exosomes (5–50 μg/ml) led to reduction in IFNG release; 100 μg/ml was statistically neutral, and 500 μg/ml D283 exosomes led to increased IFNG release from the T cells. This evidence concerns the gene IFNG and medulloblastoma.