May play a role in protein trafficking. May act as a linker molecule between the submembranous matrix on the luminal side of zymogen granule membrane (ZGM) and aggregated secretory proteins during granule formation in the TGN.
Subcellular locations: Secreted, Extracellular space, Extracellular matrix, Zymogen granule lumen, Golgi apparatus lumen
Highly expressed in liver. Detected at lower levels in colon, ileum and jejunum.