Determination of optimal time point for rhIL21-response for the 6 genes identified as preferred biomarkers. This time point experiment was done using 5 of the donors shown in Figure 2. Earlier pilot studies had suggested that stimulation for 30 minutes was significantly sub-optimal. There was no significant difference in response between all doses tested (30, 10, and 3 ng/mL). The lowest dose of rhIL21 that elicits a response has therefore not been determined.