FAM3C, also known as ILEI, is a member of theFAM3 family. It can be detected in resent in most secretory epithelia. FAM3C may be involved in retinal laminar formation. It promotes epithelial to mesenchymal transition. A change in expression of FAM3C has been noted in pancreatic cancer-derived cells. ILEI is overexpressed and/or altered in intracellular localization in multiple human tumors, an event strongly correlated to invasion/EMT, metastasis formation, and survival in human colon and breast cancer.