MFG-E8 consists of two repeated EGF-like domains on the terminal side and tandem discoidin-like (C-) domains homologous to the C1 and C2 domains of coagulation factor V and VIII. The C2 domain can mediate Ca2+-independent binding to PS. MFG-E8 expression is up-regulated in lactating mammary gland, and has been detected in other tissues such as brain, lung, heart, kidney and spleen in mouse, bovine and human.