extracellular matrix obsolete collagen-containing extracellular matrix https://github.com/geneontology/go-ontology/issues/29475 true This term was obsoleted because it was not clearly defined and usage has been inconsistent. cellular_component GO:0062023 OBSOLETE. An extracellular matrix consisting mainly of proteins (especially collagen) and glycosaminoglycans (mostly as proteoglycans) that provides not only essential physical scaffolding for the cellular constituents but can also initiate crucial biochemical and biomechanical cues required for tissue morphogenesis, differentiation and homeostasis. The components are secreted by cells in the vicinity and form a sheet underlying or overlying cells such as endothelial and epithelial cells. 2018-04-13T12:47:21Z collagen-containing ECM dph