Glypican-3 encodes a putative extracellular proteoglycan that is inferred to play an important role in growth control in embryonic mesodermal tissues in which it is selectively expressed. It appears to form a complex with insulin-like growth factor and hence modulate IGF2 action. Glypican-3 is the human homolog of OCI-5, a GPI-linked proteoglycan first isolated from rat intestine. Originally identified as the molecular basis for Simpson-Golabi-Behmel syndrome (SGBS) also called Simpson dysmorphia syndrome (SDYS).