Hyaluronic acid also called hyaluronan, is an anionic, nonsulfated glycosaminoglycan distributed widely throughout connective, epithelial, and neural tissues. It is unique among glycosaminoglycans therein it's nonsulfated, forms within the cell wall rather than the Golgi body, and may be very large: human synovial HA averages about 7 million Da per molecule, or about 20000 disaccharide monomers, while other sources mention 3–4 million Da. As one of the chief components of the extracellular matrix, hyaluronan contributes significantly to cell proliferation and migration, and should even be involved within the progression of some malignant tumors. The average 70 kg (154 lb) person has roughly 15 grams of hyaluronan within the body, one-third of which is turned over (degraded and synthesized) a day. Hyaluronic acid is additionally a component of the A streptococcal extracellular capsule and is believed to play a task in virulence.
