Journal of Histochemistry & Cytochemistry 60(12) 908 –915 © The Author(s) 2012 Reprints and permission: sagepub.com/journalsPermissions.nav

Heparan sulfate is probably the most complex carbohydrate of the Bilateria. This arises not from the structure of the basic polymer, which is a repeating disaccharide, but from the further modifications, most notably sulfation. All multi-cellular animals possess heparan sulfate, and genetic experi-ments in invertebrates such as Caenorhabditis elegans, as well as the mouse, show that it is indispensable for life (Lin et al. 2000; Kitagawa et al. 2007). Almost certainly this derives from its ability to interact with a plethora of ligands belonging to many protein families (Esko and Selleck 2002). Examples from growth factors, chemokines, cytokines, mor-phogens, extracellular matrix glycoproteins and collagens, enzymes as diverse as metzincins, and lipases are recorded (Esko and Selleck 2002; Bishop et al. 2007; Couchman 2010). Moreover, a diverse array of pathogens use hepara