Cell surface heparan sulfate proteoglycans are composed of a membrane-associated protein core substituted with a variable number of heparan sulfate chains. Members of the glypican-related integral membrane proteoglycan family (GRIPS) contain a core protein anchored to the cytoplasmic membrane via a glycosyl phosphatidylinositol linkage. These proteins may play a role in the control of cell division and growth regulation.

Moreover, athymic mice lacking Gpc1 exhibited decreased tumor angiogenesis and metastases following intrapancreatic implantation with human pancreatic cancer cells and fewer pulmonary metastases following intravenous injection of mouse melanoma cells.