Versican (chondroitin sulfate proteoglycan 2) is a large extracellular matrix proteoglycan involved in cell growthand differentiation. Important as a structural molecule,versican creates loose and hydrated matrices during keyevents in development and disease. The protein containshyaluronic acid and glycosminoglycan-binding domains,epidermal growth factor-like repeats, a Lectinlikesequence and a complement regulatory protein-likedomain. Splice variants differ greatly in length anddegree of modification by glycoaminoglycan chains.Accumulation around smooth muscle cells in lesions ofathero-sclerosis suggests a role for versican inatherogenesis. Versican, differentially expressed inhuman melanoma, plays a role in tumor developmentand may be a reliable marker for clinical diagnosis. Theorganization of HA- and versican-rich pericellularmatrices may faciliatate migration and mitosis bydiminishing cell surface adhesivity and affecting cellshape through steric exclusion and the viscous properties of HA proteoglycan gels.