Anti-ST1 antibodies enable researchers to detect and measure the ST1 antigen in biological samples. This target is a reported synonym of the SDCBP gene, which encodes syndecan binding protein. This protein is known to function in cytoskeleton organization and chemical synaptic transmission, among other biological roles. The human version of ST1 has a canonical amino acid length of 298 residues and a protein mass of 32.4 kilodaltons, although 3 isoforms have been identified. It is reported to be notably expressed in many tissues, such as the colon and skin. Other names for this target antigen include MDA-9 and MDA9.