CD4 and neoplasm: Both CD4+ cell and Treg (a subset of CD4+ with FoxP3+, also a subset of CD25+ with FoxP3+) depletion inhibited tumor growth (Supplemental Fig. 6B,C respectively), with Treg depletion inducing almost complete inhibition, suggesting that Treg plays important role in promoting MC38 tumor growth, consistent with the response observed with anti-CD4 and anti-CD25 antibody above (Fig. 3C).