Upon recruitment and activation in the tumour microenvironment, Tregs exert their immunosuppressive activities via various mechanisms including (i) secretion of soluble immunosuppressive cytokines such as transforming growth factor beta (TGF-β) [129], interleukin-10 (IL-10), and interleukin-35 (IL-35), (ii) modulation of DCs, (iii) metabolic disruption, and (iv) suppression by direct cytolysis [130, 131]. This evidence concerns the gene TGFB1 and neoplasm.