Immunotherapeutic approaches can therefore be impeded by an unfavorable composition of the intratumoral immune milieu: while regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs) repress a successful immune intervention and promote tumor progression, natural killer (NK) cells and T helper (Th) 1 CD4+/CD8+ lymphocytes are potent mediators of anti-tumor activity [1-3]. The gene discussed is CD4; the disease is neoplasm.