CD8 dependence of neoepitope-elicited tumor immunity was tested in the case of the peptide TGAARFDEF (derived from Gtf2b) by depletion of neoepitope-immunized mice by anti-CD8 depleting antibody or an isotype control antibody during the priming phase alone, as described in the Methods. The gene discussed is CD8A; the disease is neoplasm.