extracellular region extracellular Wikipedia:Extracellular cellular_component Note that this term is intended to annotate gene products that are not attached to the cell surface. For gene products from multicellular organisms which are secreted from a cell but retained within the organism (i.e. released into the interstitial fluid or blood), consider the cellular component term 'extracellular space ; GO:0005615'. GO:0005576 The space external to the outermost structure of a cell. For cells without external protective or external encapsulating structures this refers to space outside of the plasma membrane. This term covers the host cell environment outside an intracellular parasite. cellular anatomical entity