Tumor cells by secretion of TGF-β and prostaglandin E2 induce DCs to differentiate into regulatory DCs with a CD11c(low)CD11b(high) phenotype (also named plasmocytoid DC) and high expressions of IL-10, VEGF, and arginase I. These regulatory plasmocytoid DCs inhibited CD4+ T cell proliferation [49] and thus act protumorigenic. This evidence concerns the gene IL10 and neoplasm.