CD8A and neoplasm: Therapeutic vaccination for CTL induction holds great promise for cancer therapy8,9 but has delivered inconsistent therapeutic benefits, including failure of large clinical trials.10, 11, 12, 13 Despite induction of sizeable tumor antigen-specific CD8+ T cell frequencies by modalities such as adjuvanted peptides,14 inefficient tumor infiltration has curtailed the clinical efficacy of these cells.15