INSL4 Proteins and Enzymes

Early placental insulin-like protein (INSL4), also called EPIL, is an insulin superfamily member that is expressed only in higher primates. ProINSL4 is a 114 amino acid (aa) form which retains the central C-peptide, while INSL4 is a 56 aa form containing only processed, covalently linked A and B peptides. Both forms are normally expressed only by uterus and placenta, especially by syncytiotrophoblasts. High serum proINSL4 in some pregnancy complications has been reported.