The 1D11.16.8 monoclonal antibody reacts with mouse, human, rat, monkey, hamster, canine and bovine TGF-β (transforming growth factor beta) isoforms 1, 2 and 3. TGF-β is a multifunctional cytokine that regulates the proliferation of epithelial cells, endothelial cells, fibroblasts, neurons, lymphoid cells including T lymphocytes and NK cells, and other hematopoietic cell types. TGF-β also regulates the activities of activated macrophages and the development of regulatory T cells. Additionally, TGF-β plays roles in immune function, tissue remodeling and wound repair. TGF-β exists as five highly similar isoforms (TGF-β 1-5) with homologies of 70-80%. TGF-β1 is synthesized by the enzymatic cleavage of a long precursor TGF-β1 polypeptide encoded by the TGFB1 gene which yields the mature protein and the Latency Associated Peptide (LAP). The LAP and mature TGF-β1 non-covalently associate during secretion. TGF-β is ubiquitously expressed by many cell types including macrophages and platelets which express high levels of TGF-β. TGF-β signaling has been shown to plays roles in cancer, autoimmune diseases, asthma, heart disease, and diabetes. Its importance is illustrated by TGF-β knockout mice which show defects in hematopoiesis and endothelial differentiation, and die of overwhelming inflammation. The 1D11.16.8 monoclonal antibody is a neutralizing antibody.