It has also been reported that tumor cells can inhibit cytotoxic T lymphocyte infiltration by producing immunosuppressive cytokines, such as vascular endothelial growth factor (VEGF), transforming growth factor-β (TGF-β), or IL-10, and by reducing IL-2, a cytokine that can maintain cytotoxic T lymphocyte function [58]. This evidence concerns the gene TGFB1 and neoplasm.