Hyaluronan (HA), a linear non-sulfated glycosaminoglycan, participates in a variety of
biological processes in the skin, such as cell-matrix interactions and activation of
chemokines/cytokines, enzymes, and growth factors. In these activation events, HA acts as a
damage-associated molecular pattern (DAMP). This review discusses the progress in
functional research on HA, and its associated factors, in several aspects of cutaneous
biology; eg, immunity and wound repair.