Extracellular matrix protein that seems to be a ligand for ITGA8:ITGB1, ITGAV:ITGB1 and ITGA4:ITGB1 (By similarity) (PubMed:17909022). Involved in neurite outgrowth and cell migration in hippocampal explants (By similarity). During endochondral bone formation, inhibits proliferation and differentiation of proteoblasts mediated by canonical WNT signaling (By similarity). In tumors, stimulates angiogenesis by elongation, migration and sprouting of endothelial cells (PubMed:19884327). Expressed in most mammary tumors, may facilitate tumorigenesis by supporting the migratory behavior of breast cancer cells (PubMed:17909022).