Description: Human TGF beta 1 (Transforming Growth Factor beta 1) is a member of a superfamily of homologous, disulfide-linked, homodimeric proteins that regulate the proliferation and differentiation of normal and transformed cells. Human TGF beta 1 is a 25 kDa protein with each subunit containing 112 aa residues. TGF beta 1 is secreted from the many cell types in a complex with LAP (Latency Associated Peptide) and also with LTBP (latent TGF beta binding protein). Disassociation is thought to happen in the extracellular matrix via proteases and/or integrins. Regulatory T cells are a recently identified source of TGF beta 1 thought to be a key player in their suppressive functions. TGF beta 1 binds through TGF beta receptors (of which there is a large family). The protein is highly conserved across all mammalian species.