CD8A and neoplasm: A reduction in the ability of elderly CD11c+ cells to stimulate anti-tumor effector T cells is consistent with other studies showing that elderly bone marrow-derived DCs are less efficient in stimulating tumor antigen-specific CD8+ and CD4+ T cells and mediating tumor regression (6, 7), and that administration of DC vaccines to elderly mice results in weak cytotoxic CD8+ T cell activity and does not slow tumor growth (8, 9).