In order to infer which component of the OpTmizerTM recipe played a more direct role in contributing to the changes in TIM-3 expression on NK cells, we modified OpTmizerTM medium by removing either the recommended cytokine supplement (OpTmizerTM (OpT) w/o supplements) or removing IL-15 alone (OpT w/o IL-15) and then exposed NK cells activated in these media to GBM cells as before. This evidence concerns the gene IL15 and glioblastoma.