Transforming growth factors--an overview.

Transforming Growth Factors (TGFs) are a sub-group of a larger family of protein hormones. Two major types of TGF are currently known, alpha-TGF and beta-TGF. Biologically their most important property is to act synergistically to induce anchorage-independent growth of target cells otherwise incapable of such growth. Since this growth parameter is well correlated with tumorigenicity in vivo, these factors may play a role in cancer development. Biochemically both alpha-TGF and beta-TGF have been well characterised in some types of cells and tissues. Their role in normal and neoplastic growth is actively studied.