CD4 and neoplasm: In the first set of experiments, we systematically depleted syngeneic tumor-bearing mice (MC38, Hepa1-6, CT-26, and EMT-6) of different immune-lineages using the following reagents16,18: (1) anti-CD8 (2.43) antibody for removing CD8+ CTLs; (2) anti-CD4 (GK1.5) antibody for removing CD4+ T-cells; (3) anti-CD25 antibody for CD25+ cells that are enriched for Treg18, (4) either anti-NK1.1 or anti-Asialo-GM1 antibody for removing NK cells, and (5) clodronate liposomes for depletion of macrophage.