Most T cell clones expressing highly represented TCRs in IFN‐γ‐treated mice at day 12 map onto the cytotoxic CD8 cluster (Fig 4F), possibly representing tumor‐specific T cells that may help in early leukemia control, but became unable to persist while leukemia progressed, as evidenced by downregulation of transcriptional programs associated with the transcription factor Tox (Table EV5, cytotoxic CD8). Here, CD8A is linked to neoplasm.