Table 3.

Overview of Selected Potential Phenotypic Markers

	Antibody*	Function†	Specificity in Vasculature†	Fibroblastic Cells	Myofibroblastic Cells	C‐SMCs
Mesenchymal lineage	1. Vimentin 12 , 13 , 14	Stabilization of cytoskeletal interactions and maintenance of cell shape and integrity of the cytoplasm 48 , 49	Expressed in leukocytes and endothelial cells as well 50 , 51
	2. S100A4/FSP‐1 15 , 16 , 17	Involved in proteolytic activity during ECM remodeling and cell migration, proliferation, differentiation, and contractility 52 , 53 , 54	Expressed in leukocytes as well 52 , 54 , 55
	3. CD90/Thy‐1 15 , 18 , 19	Involved in cell adhesion and cell communication 56	Expressed in endothelial cells as well 57
	4. FAP 20 , 21 , 22	Thought to promote cellular invasion through the ECM 58	Expressed in leukocytes as well 59
Contractile apparatus	5. αSMA 23 , 24 , 25	Force generation 60 , 61 , 62	Expressed in macrophage‐like phenotype (foam cells) as well 63 , 64
	6. Smemb 25 , 26 , 27	Thought to be involved in diverse processes, including cytokinesis, cell shape, and secretion 65	Restricted to mesenchymal cells 66
	7. SM‐MHC 28 , 29 , 30	Force generation 17 , 67	Restricted to mesenchymal cells 68
Accessory contractile	8. h1‐Calponin 28 , 31 , 32	Regulation and modulation of smooth muscle contraction 69	Restricted to mesenchymal cells 70
	9. h‐Caldesmon 13 , 33 , 34	Regulation of smooth muscle contraction 71	Restricted to mesenchymal cells 72
	10. Desmin 13 , 34 , 35	Maintenance of myofibril, myofiber, and whole muscle tissue structural and functional integrity 73 , 74	Restricted to mesenchymal cells (in vasculature) 75
	11. SM22α 22 , 28 , 29	Involved in the reorganization of the actin cytoskeleton and cell contractility 76 , 77	Restricted to mesenchymal cells 78
	12. Smoothelin‐B 28 , 36 , 37	Associates with stress fibers and constitutes part of the cytoskeleton 79	Restricted to mesenchymal cells 80
	13. a‐Tropomyosin 27 , 38 , 39	Regulation of smooth muscle contraction 81	Restricted to mesenchymal cells 82
	14. Telokin 40 , 41 , 42	Involved in initiation or maintenance of smooth muscle relaxation as well as in contraction 83 , 84	Restricted to mesenchymal cells 85
Focal adhesion	15. Paxillin 43 , 44 , 45	Focal adhesion protein involved in cell‐matrix adhesion and presumably coordination of transmission of downstream signals in cell movement and migration 86	Expressed in leukocytes, endothelial cells, and epithelial cells as well 87
	16. Vinculin 38 , 46 , 47	F‐actin binding protein involved in cell‐matrix adhesion and cell‐cell interactions 88	Expressed in leukocytes, endothelial cells, and epithelial cells as well 89

The selected phenotypical markers are divided in 3 main groups, of which the contractile markers are subdivided on the basis of whether they are part of the contractile apparatus or they are accessory proteins that regulate actin‐myosin interaction. Fibroblastic cells, myofibroblastic cells, and C‐SMCs were evaluated on their reported discriminative power: dark gray represents controversy over discriminating ability of the marker, and light gray represents consensus that the marker is nondiscriminative. CD indicates cluster of differentiation; C‐SMC, contractile smooth muscle cell; ECM, extracellular membrane; FAP, fibroblast activation protein; FSP‐1, fibroblast‐specific protein‐1; αSMA, α‐smooth muscle actin; SM22α, smooth muscle protein 22α; Smemb, nonmuscle myosin heavy chain; SM‐MHC, smooth muscle myosin heavy chain; and Thy‐1, thymocyte differentiation antigen 1.

^aReferences from systematic review.

^bSupplementary references (not from systematic review).