CD8A and neoplasm: In a preliminary vaccination trial following the schedule in Figure8A, RP phages of varying adjuvanticity but the same antigen density (CG0/rAE, CG09/rAE, CG27/rAE, and CpG40/rAE) elicited low Adpgk‐specific CD8+ T cell frequencies (Figure S13, Supporting Information), suggesting that antigen density might be the limiting factor for robust anti‐tumor CD8+ T cell response.