Table 2.

Markers and signature genes of HNSCC CAFs.

CAFs markers/ signature genes	Description of markers/ genes	Expression level in HNSCC CAFs	Biological functions/ notes	References
Vimentin	Type III intermediate filament protein	Upregulated	Promoting tumor EMT/ poor outcome	[70]
α-SMA	Actin isoform	Upregulated	Related with CAFs activation/ poor outcome	[136]
FSP1	Calcium-binding protein containing 2 EF-hand calcium-binding motifs	Upregulated	Identifying CAFs in vitro	[70]
FAP	Membrane-bound gelatinase	Upregulated	Poor outcome	[60, 136]
PDGFRα	Protein tyrosine kinase receptor	Upregulated	Mediating mesenchymal stromal cell chemotaxis to tumor	[137]
PDGFRβ	Protein tyrosine kinase receptor	Upregulated	Signing stromal activation in tumor	[60, 138]
Caveolin-1	Scaffolding protein within caveolar membranes	Upregulated	Inhibited the TGF-β/SMAD signaling and promoting CAFs activation	[134, 139]
Periostin	Secreted extracellular matrix protein, a ligand for α-V/β-3 and α-V/β-5 integrins	Upregulated	Promoting tumor stemness/ poor outcome	[60, 85]
Podoplanin	Mucin-type protein, heavily O-glycosylated glycoprotein	There is no relationship directly	Promoting lymph nodes metastasis/ poor outcome	[140]
CD44	Non-kinase transmembrane glycoprotein	Upregulated	Mediating immunosuppression/ poor outcome	[141]
AKT3	A serine/ threonine protein kinas that modulates various cellular responses via the PI3K-AKT pathway	Upregulated	Mediating immunosuppression and promoting myofibroblastic phenotype/ poor outcome	[60]
COX-2	An inducible enzyme responsible for the production of prostaglandins at sites of inflammation and wound‐healing.	Upregulated	Promoting tumor migration, angiogenesis and invasiveness/ poor outcome	[95, 125]