CD8A and neoplasm: Since tumor vaccine seeks to induce CD8 T cell activation against tumor Ags, DC-mediated cross-presentation of tumor Ags is required [8, 14] To promote activation of CD8 T cells, an effective adjuvant must be given together with Ag peptide, formulated in a manner that facilitates entry of Ags into the MHC class I processing pathway, trigger DC activation and maturation.