Recombinant Human TGFβ1 is a 25.0 kDa protein composed two identital 112 amino acid polypeptide chains linked by a single disulfide bond. Human TGFβ exists as three isoforms (1,2,3), that are 70-80% homologous; the Simoa Human TGFβ assay recognizes all 3 isoforms. As part of a Kinase complex, TGFβ initiates a signal cascade that upregulates target gene expression. Target genes activated by this cascade impact a wide range of functions including cell invasion, environmental modification, differentiation, proliferation, and immune cell activation. Modification of the normal TGFβ pathway is associated with cancer development.