Syndecans have attached heparan sulfate (HS) and to a lesser extent chondroitin sulfate (CS) chains. These allow interactions with a large number of proteins. Various enzymes involved in post-translational HS chain modifications produce unique binding motifs that selectively recognize different proteins (Tkachenko et al. 2005). Syndecans binds with extracellular matrix proteins, including fibronectin (Human syndecan-1, Saunders & Bernfield 1988; rat syndecan-4 in Woods et al. 2000; rat syndecan-2 to bovine fibronectin in Klass & Woods 2000). Syndecan-1 functions to regulate integrin activity and fibronectin fibril assembly (Stepp et al. 2010).