USAG1 (uterine sensitization associated gene 1), also known asSOSTDC1 (sclerostin domain-containing 1), Ectodin, is a secreted protein with a glycosylated Nterminus that contains a Cterminal cysteine knot domain. This Cterminal cysteine knot domain is present in numerous growth factors, including TGFbeta, NGF, PDGF, vWF, NDP, and mucin2, and involved in dimerization, receptor binding, and signal transduction. SOSTDC1 negatively regulates BMP signaling during cellular proliferation, differentiation, and apoptosis in several biological processes (such as dentary morphogenesis, embryo implantation in the endometrium, and healing of bone fractures) [8]. In addition, SOSTDC1 might also involve cancer development processes through the regulation of the Wnt pathway. - Proteine/Peptide