(A) Representative gating strategy used to identify the percentage of CD107a expressing NK cells in a degranulation assay where healthy donor PBMC are combined with a target cell. (B) CD107a expression by the NK cells where PBMC are combined with: i) medium alone (negative control), ii) MHC class I negative cell line K562 (positive control), iii) vehicle-treated NALM-6, iv) Bortezomib-treated NALM-6. NK degranulation against vehicle, drug, and drug in the presence of NKG2D blocking antibody is compared for (C) Bortezomib, (D) Valproate and (E) Troglitazone (*p<0.05, **p<0.01, n≥3 for all comparisons). % specific degranulation = %CD107a+ with target - %CD107a+ with medium alone.