Table 1.

Marker proteins:DDR2, discoidin domain receptor 2; PDGFRα, platelet derived growth factor receptor α; TCF21, Transcription factor 21; FSP1, fibroblast specific protein 1; Sca-1, stem cell antigen-1; αSMA, α smooth muscle actin; TNC, tenascin-C. Modified from [48,55,73].

Markers/Mouse Lines	Functions	Expression in CFs	Expression in Other Cells in the Heart	References
Periostin	ECM protein	activated CFs	Epicardium	[55,68,73]
CD90	Cell adhesion and cell communication	Resting and activated CFs	Pericytes, VSMC, ECs, immune cells	[73,74]
DDR2	A membrane collagen-binding tyrosine kinase receptor	Resting CFs	Epicardium	[48,75,76]
PDGFRα	Tyrosine kinase receptor	CFs during development and after injury	Cardiac progenitor cells	[47,68,77,78]
TCF21	Involved in epithelial-mesenchymal transition	Resting CFs	Epicardium	[79,80]
FSP1	Calcium binding and promote filament depolymerization	Resting and activated CFs	Pericytes, VSMC, ECs, immune cells	[81,82]
Sca-1	Stem cell antigen	Resting and activated CFs	Cardiac progenitor cells	[83,84]
Fibronectin	ECM protein	Resting and activated CFs	ECs	[55,73,85]
Vimentin	Intermediate filament protein	Resting and activated CFs	Pericytes, VSMC, ECs	[86,87]
collagen types I and III	ECM protein	Resting and activated CFs	Pericytes, VSMC, ECs, cardiomyocytes	[55,88]
αSMA	Isoforms of actin filament	activated CFs	Pericytes, VSMC, cardiomyocytes, Epicardium	[2,29,89]
TNC	ECM protein	activated CFs	Pericytes, VSMC,	[6,7,90]