Pre- and post-vaccination CD8+ T cell responses to tumor antigen-derived peptides in patient LAU 455. Pre- and post-vaccination (day 39) PBMC samples from patient LAU 455 were analyzed either ex vivo (upper panels) or one week after in vitro stimulation with the corresponding peptide (1 µM) (lower panels). Staining with anti-CD45RA^FITC mAb and with the indicated A2/peptide multimers^PE on gated CD8+ T cells is shown in the upper panels. Staining with anti-CD8^FITC and with the indicated A2/peptide multimers^PE on gated lymphocytes is shown in the lower panels.