HLA-restricted and epitope specific CTL reactivity in breast cancer patients. T lymphocytes were generated from the peripheral blood of six patients with localized breast cancer, as described in Methods. These CTLs were tested for their ability to lyse Tap-deficient T2 cells loaded with individual BA-46 peptides, the HLA-A2.1–restricted melanoma-associated tyrosinase peptide, and the human NK target cell line K562. Each bar represents the average of triplicates. The experiment was performed once.