TGFB1 and neoplasm: This antitumorigenic effect is mediated through the activation of cyclin-dependent kinase inhibitors specifically p21 & p27, which disrupt the action of mitogenic growth factors such as insulin-like growth factor 1 (IGF-1) and epidermal growth factor (EGF), while simultaneously enhancing the tumour-suppressive effects of transforming growth factor-beta (TGF-β).