Since myeloid-derived suppressor cell (MDSCs) and regulatory T(reg) cells are both known to protect tumors from CTL-mediated elimination and to promote tumor growth, ideal immunotherapies should be able to selectively enhance tumor production of CTL-attracting chemokines, without enhancing local levels of CXCL8, CXCL12 and CCL22, the chemokines mediating local attraction of MDSC and Treg to tumors [26-30]. This evidence concerns the gene CXCL12 and neoplasm.