Transforming Growth Factor-Beta (TGF-beta) is the general name for a family of naturally-occurring polypeptides which have multiple regulatory effects on cell proliferation and differentiation. Over the last decade it has become apparent that TGF-betas can be produced by most cell types and exert a wide range of effects in a context-dependent autocrine, paracrine or endocrine fashion via interactions with distinct receptors on the cell surface. This review summarizes current knowledge concerning the molecular and cellular biology of TGF-beta 3, the most recently described mammalian isoform, and focuses on those physiological actions which may lead to clinical applications, particularly in the indication areas of wound healing and chemoprotection.