Surface-exposed blood and tissue proteins

Surface-exposed blood and tissue proteins represent a broad and heterogeneous class of proteins that are accessible to the extracellular environment, including the plasma and interstitial fluid (ResearchGate, 2010). This category encompasses cell surface receptors, adhesion molecules, plasma proteins, and extracellular matrix (ECM) components (MDPI, 2022; NIH, 2013). Because of their accessibility, these proteins are the primary targets for most therapeutic modalities, particularly monoclonal antibodies and small molecules that do not readily cross the cell membrane (The Scientist, 2021; NIH, 2021). They play fundamental roles in physiological processes such as signal transduction, cell-cell communication, immune surveillance, and structural support (ASH Publications, 2018). In pathological states, the expression or function of these proteins is often altered; for instance, many cancer therapies target overexpressed surface antigens to achieve selective tumor killing (Blood Cancer United, 2025; IIAR Journals, 2010). Additionally, pathogens often exploit surface-exposed host proteins to facilitate attachment, invasion, and immune evasion (Frontiers in Microbiology, 2022; BioRxiv, 2021). Understanding the surfaceome is critical for drug discovery, as it defines the biological identity of cells and their interactions with the systemic environment (ResearchGate, 2010).

Other names

Extracellular proteinsPlasma proteinsCell surface proteinsSurfaceomeExtracellular matrix (ECM) proteinsSurface-exposed proteome

Drugs targeting these proteins typically act by binding to extracellular or membrane-bound epitopes to neutralize ligands, antagonize receptors, or facilitate targeted delivery and immune-mediated cell clearance.