TGFB1 and neoplasm: It was observed that fibroblast-derived soluble factors such as TGF-β, tumor necrosis factor alpha (TNFα), and interleukin-6 (IL-6) coordinate contact-independent suppression of tumor growth in a paracrine manner, thus suggesting that the default function of normal fibroblasts is to alleviate the transformation of normal or pre-malignant cells into tumor ones.