A factor synthesized in a wide variety of Tissues. It acts synergistically with TGF-alpha in inducing phenotypic transformation and can also act as a negative autocrine Growth factor. TGF-beta has a potential Role in embryonal development, cellular differentiation, Hormone Secretion, and immune function. TGF-beta is found mostly as homodimer Forms of separate Gene products TGF-beta1, TGF-beta2 or TGF-beta3. Heterodimers composed of TGF-beta1 and 2 (TGF-beta1.2) or of TGF-beta2 and 3 (TGF-beta2.3) have been isolated. The TGF-beta Proteins are synthesized as precursor Proteins.