Detection of Bcl-2–specific CTLs by granzyme B ELISPOT. T lymphocytes from 4 different late-stage patients with breast cancer (b19, b20, b22, b16) and a healthy control (h1) were stimulated once with peptide before being plated at 10⁵ cells per well in triplicates either without or with peptide Bcl₂₀₈ (A) or Bcl₂₁₄ (B). The average number of peptide-specific granzyme B 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 ⋄.