To investigate the CD8+ T cell response against DEK in mice that had received a cell-based cancer vaccine, A/J mice were given two weekly subcutaneous (s.c.)injections of 2 × 106 irradiated AGN2a-CD80/CD86 cells cultured in DMEM supplemented with 2% mouse serum or 10% FBS, and Treg activity inhibited by the i.p. injection of clone PC61 anti-CD25 antibody three days prior to the first vaccination. This evidence concerns the gene CD86 and cancer.