Figure 1 is a representative tetramer staining analysis showing increased CD8+ PSA146-154-tetramer+ T-cells postvaccine (week 26) compared to prevaccine following in vitro sensitization of PBMC with PSA146-154 peptide. Tetramer responses were not detectable in unstimulated PBMC population. Comparable results were observed by Lau and coworkers in a peptide-DC based melanoma study [7]. The gene discussed is CD8A; the disease is melanoma.