FLLL32 did not adversely affect viability of immune cells or NK cell function. Viability of normal donor PBMCs treated with FLLL32, curcumin (Cur; 20μM) or DMSO was assessed by (A) flow cytometric analysis following annexin V/PI staining and (B) by immunoblot analysis. (C) Viability of normal donor NK cells as measured by trypan blue staining after 24 hours in the presence of IL-2 (1 nM) and either FLLL32 (5μM) or DMSO. Data are presented as the mean percentage of viable NK cells and error bars represent the standard deviation from n = 3 individual donors. (D) NK cell mediated Gzmb and IFN μ secretion was not altered in the presence of FLLL32 (5μM) as measured by ELISPOT against K562 targets (10:1 E:T ratio). Data are presented as the mean number of Gzmb or IFN-γ spots and error bars represent the standard deviation from n = 3 individual donors.