Low and intermediate molecular weight HA (2 × 104–4.5 × 105 Da) stimulates gene expression in macrophages, endothelial cells, eosinophils and certain epithelial cells (McKee et al., 1996; Oertli et al., 1998). Hyaluronan degradation products are purported to contribute to scar formation. Fetal wounds heal without scar formation and wound fluid HA is of high molecular weight. When hyaluronidase is added to generate HA fragments, there is increased scar formation. These data support the theory that high molecular weight HA promotes cell quiescence and supports tissue integrity, whereas generation of HA breakdown products is a signal that injury has occurred and initiates an inflammatory response (Chen and Abatangelo, 1999