2863872 HSPG heparan sulfate proteoglycan 953 2670823 HSPGs heparan sulfate proteoglycans 942 1087642 HSP heparan sulfate proteoglycan 11 4040056 HSPGact heparan sulfate proteoglycans 5 1548064 HSPG's heparan sulfate proteoglycans 2 2439602 HPSGs heparan sulfate proteoglycans 1 2864064 HSPs heparan sulfate proteoglycans 1 3952824 HeSPGs heparan sulfate proteoglycans 1