Members of the Transforming growth factor beta (TGFB) family of cytokines are multifunctional peptides that regulate proliferation, differentiation, adhesion, migration, and other functions in many cell types. Many cells have TGFB receptors, and the protein positively and negatively regulates many other growth factors. The secreted protein is cleaved into a latency-associated peptide (LAP) and a mature TGFB1 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 TGFB1 homodimer. The mature peptide may also form heterodimers with other TGFB family members. TGFB1 is frequently upregulated in tumor cells, and mutations in this gene result in Camurati-Engelmann disease. Recombinant mouse TGFB1 protein, fused to His-tag at N-terminus, was expressed in E.coli.