Gene expression analysis of peripheral blood mononuclear cells (PBMCs) from melanoma patients treated with dacarbazine and a peptide-based vaccine revealed, by one day after chemotherapy, increased expression of immunoregulatory factors that can account for the enhancement of tumor antigen-specific CD8 T cell responses observed in those patients, as compared with patients treated with vaccine alone [33]. The gene discussed is CD8A; the disease is neoplasm.