Editing Extracellular matrix (section)

===Non-proteoglycan polysaccharide===
====Hyaluronic acid====
[[Hyaluronic acid]] (or "hyaluronan") is a [[polysaccharide]] consisting of alternating residues of D-glucuronic acid and N-acetylglucosamine, and unlike other GAGs, is not found as a proteoglycan. Hyaluronic acid in the extracellular space confers upon tissues the ability to resist compression by providing a counteracting [[turgor]] (swelling) force by absorbing significant amounts of water. Hyaluronic acid is thus found in abundance in the ECM of load-bearing joints. It is also a chief component of the interstitial gel. Hyaluronic acid is found on the inner surface of the cell membrane and is translocated out of the cell during biosynthesis.<ref name=MCB>{{cite book |vauthors=Lodish H, Berk A, Matsudaira P, Kaiser CA, Krieger M, Scott MP, Zipursky SL, Darnell J | title = Molecular Cell Biology |year=2008 |url=https://archive.org/details/molecularcellbio00harv_624 |url-access=limited | edition = 5th | chapter = Integrating Cells Into Tissues | location = New York | publisher = WH Freeman and Company | pages = [https://archive.org/details/molecularcellbio00harv_624/page/n193 197]–234}}</ref>

Hyaluronic acid acts as an environmental cue that regulates cell behavior during embryonic development, healing processes, [[inflammation]], and [[tumor]] development. It interacts with a specific transmembrane receptor, [[CD44]].<ref>{{cite journal | vauthors = Peach RJ, Hollenbaugh D, Stamenkovic I, Aruffo A | title = Identification of hyaluronic acid binding sites in the extracellular domain of CD44 | journal = The Journal of Cell Biology | volume = 122 | issue = 1 | pages = 257–64 | date = July 1993 | pmid = 8314845 | pmc = 2119597 | doi = 10.1083/jcb.122.1.257 }}{{open access}}</ref>