For example, tumor progression-related soluble factors, including cyclooxygenase-2 (COX-2), prostaglandin E2 (PGE2), transforming growth factor-β (TGF-β), and vascular endothelial growth factor (VEGF), can deregulate dendritic cell functions to impair the presentation of tumor antigens, interfering with activation of tumor-specific CTLs [28–30]. This evidence concerns the gene TGFB1 and neoplasm.