Figure 4. Assessments of experimental variability of the cytotoxicity assays.

NK cells were isolated from three healthy individuals. These cells were activated in vitro for five days and then examined for their ability to lyse iDCs and K562 tumor cells. Percent cytotoxicity is shown as mean ± SEM. A) and B) show assays done from two healthy donors with two different E:T ratios. C) and D) show the results from a third healthy donor with repeated samples at baseline, or 3 and 8 weeks later.