TGF beta-1 (TGFB1, Transforming Growth Factor Beta 1) is a polypeptide member of the transforming growth factor beta superfamily of cytokines, found almost ubiquitously in tissues. Transforming growth factor (TGF)-b is stored in the extracellular matrix as a latent complex with its pro-domain. Activation of TGF beta-1 requires the binding of aV integrin to an RGD sequence in the prodomain and exertion of force on this domain, which is held in the extracellular matrix by latent TGF-b binding proteins. Latent forms are complexes of TGF beta-1, an amino-terminal portion of the TGF-beta precursor, designated TGF-LAP (TGF-latency associated peptide), and a specific binding protein, known as LTBP. TGF beta-1 helps regulates proliferation, differentiation, adhesion, migration in many cell types. Many cells have TGF beta receptors, and the protein positively and negatively regulates many other growth factors. TGF beta-1 is cleaved into a latency-associated peptide and a mature TGF beta-1 peptide, and is found in either a latent form composed of a TGFB1 homodimer, a LAP homodimer, and a latent TGFB1-binding protein, or in an active form composed of a TGF beta-1 homodimer. The mature peptide may also form heterodimers with other TGF beta family members. The gene for TGF beta-1 is frequently upregulated in tumor cells, and mutations in this gene result in Camurati-Engelmann disease and cystic fibrosis.