Expressed in a variety of tissues, Transforming Growth Factor-Beta Family Genes encode Transforming Growth Factor-Beta, an autocrine growth factor that can act synergistically with TGF-alpha in embryonic development, cellular differentiation, hormone secretion, and immune function. There are at least three forms of TGF-beta: TGF-beta 1, TGF-beta 2, and TGF-beta 1.2. The latter is a heterodimer of TGF-beta 1 and TGF-beta 2. (NCI) [ ]