“Transforming growth factors” (TGFs) superfamily members are responsible for causing normal fibroblasts to undergo anchorage-independent growth, a property closely associated with the transformed, or malignant, phenotype in vivo. TGF-α is originally thought to be expressed solely by tumor cells, and TGF-β is thought to be expressed in normal tissues and served to modulate the transforming process. TGF-β1 was found and charactered in the early 1980’s and this leads to the identification of two TGF-β isoforms (TGF-β2, TGF-β3) and a large family of growth factors that are essential regulators of developmental processes, physiology and disease pathogenesis.
The TGF-β Superfamily members are secreted cell-regulatory proteins which play biologically diverse roles in embryonic development, tissue differentiation and proliferation, body patterning, maintenance of pluripotency, and also can influence of cell fate in stem cell systems.
There are nearly forty TGF-β Superfamily proteins in mammalian genome which all share sequence and structural similarities. They share the same family of receptors and signaling intermediates. Subfamilies within the TGF-β superfamily are organized based on structural and sequence similarities of the mature monomer.
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