CD8⁺ T-cell responses were detected in most tumor Ag peptides used in the experimental procedure. The graph shows the maximal T-cell response detected to the different peptides. Values represent the percentage of CD137⁺CD8⁺ T cells specific to the different peptides and are calculated by subtracting the percentage of cells detected in the unstimulated population. Details of peptides studied are contained in supplemental Table 2.