Syndecans have attached heparan sulfate (HS) and to a lesser extent chondroitin sulfate (CS) chains. These allow interactions with a large number of proteins, including heparin-binding growth factors such as fibroblast growth factors (FGFs), mediating interaction with FGF receptors (Kiefer et al. 1990, Bernfield & Hooper 1991, Steinfeld et al. 1996, Chua et al. 2004). Various enzymes involved in post-translational HS chain modifications produce unique binding motifs that selectively recognize different proteins (Tkachenko et al. 2005).