Changes in frequency of tyrosinase-reactive CD8+IFN-γ+T cells following mouse tyrosinase DNA vaccination. Each point refers to the mean of triplicate values in intracellular cytokine staining assays. Most patients also underwent two peripheral blood draws at baseline one week apart prior to receiving vaccination. The values at baseline represent the mean of both of these time-points. * Refers to patients with increase in CD8+ IFN-γ + T cells.