FAM3C,also known as ILEI,is a secreted protein belonging to the cytokine-like protein family. FAM3C is a signaling cytokine with a GG domain,hydrophobic leader sequence and an N-terminal signal peptide. A change in expression of this protein has been noted in pancreatic cancer-derived cells. FAM3C has been involved in the epithelial to mesenchymal transition,and retinal laminar formation processes in vertebrates. Also,FAM3C may play an important role in inner ear development and thus be involved in cell differentiation and proliferation during inner ear embryogenesis.