Flow cytometric analysis of surface phenotype of hTERT-transduced, HPV16 E711-20–specific CTL A9-TN. Fluorescence intensity is shown for isotype control, anti-CD8α, anti-CD8β, and anti-CD25 antibody stainings, and for HLA-A2.1/MP58-66 (T A2 MP58-66) and HLA-A2.1/E711-20 (T A2 E711-20) tetramer stainings. Filled histograms represent A9-TN during the first 12 months after hTERT transduction, and open histograms represent A9-TN beyond 12 months after hTERT transduction. Flow cytometric analysis was performed 3 weeks after feeder mix stimulation.