T-cell responses against Bcl-2 as measured by IFN-γ ELISPOT. PBLs from 12 healthy individuals, 13 patients with primary breast cancer, 13 patients with late-stage breast cancer, and 2 patients with late-stage pancreatic cancer were analyzed. All individuals were HLA-A2 positive. The peptides Bcl₁₇₂ (A), Bcl₁₈₀ (B), Bcl₂₀₈ (C), and Bcl₂₁₄ (D) were examined. T lymphocytes were stimulated once with peptide before being plated at 10⁵ cells per well in triplicates either without or with peptide. The average number of peptide-specific spots (after subtraction of spots without added peptide) was calculated for each patient using the ImmunoSpot Series 2.0 Analyzer (CTL Analyzers). Responders (defined as average number of antigen-specific spots ± 1/2 standard deviation > 25 per 10⁵ lymphocytes) are marked as , whereas nonresponding individuals are marked as ⋄.