To this end, we have used MHC class I dextramers to identify both at baseline (i.e. preexisting) and during vaccinations, T cell responses (measured as % of dextramer-specific CD8+ T cells) against other HER-2/neu epitopes or against epitopes from other tumor antigens, representing intramolecular and intermolecular spreading, respectively. The gene discussed is CD8A; the disease is neoplasm.