The function of SDC3 (syndecan 3, ENSG00000162512) is as follows. Cell surface proteoglycan that may bear heparan sulfate (By similarity). May have a role in the organization of cell shape by affecting the actin cytoskeleton, possibly by transferring signals from the cell surface in a sugar-dependent mechanism. {ECO:0000250, ECO:0000269|PubMed:11527150}.