Book excerpt: Hardbound. Although hyaluronan was discovered nearly 70 years ago and has been investigated by thousands of scientists, it is very appropriate that as we enter a new millennium, the study of the biology and chemistry of hyaluronan has entered a renaissance period. The driving force behind the symposium was to redefine the properties and complex biological roles of hyaluronan, its interactions with other molecules of the extracellular matrix and its increasing use to treat various pathologies. For many decades hyaluronan was considered to be merely a structural component of many tissues, certainly important for the normal function of our eyes and joints, but of relatively little interest to scientists trying to understand complex multicellular processes. That view has been dramatically changed by several unexpected discoveries: that several cell surface receptors specifically recognize hyaluronan; that small hyaluronan oligosaccharides stimulate angiogenes