of the other extracellular matrix constituents analysed in hr9 culture supernatants ( collagen type iv , a heparan sulfate proteoglycan and fibronectin ) none could be shown to promote adhesion , when coated as substrate , suggesting that yet unidentified compounds are responsible for l1- or n-cam-mediated cell adhesion .
C0015350
extracellular matrix
C0062503
heparan sulfate proteoglycan