TGFB1 is the prototype member of the TGF-beta super-family that includes Inhibins, Activin A, MIS (Müllerian inhibiting substance), BMP (bone morphogenetic proteins), dpp (decapentaplegic) and Vg-1. TGFB1 is the most potent known growth inhibitor for normal and transformed epithelial cells, endothelial cells, fibroblasts, neuronal cells, lymphoid cells and other hematopoietic cell types. TGF-beta inhibits the proliferation of T lymphocytes by down-regulating predominantly IL2 mediated proliferative signals and also inhibits the growth of natural killer cells. Recombinant human TGFB1 is a disulfide linked homodimer protein that migrates at approximately 26kDa under non-reducing conditions.