Table 2

Ligand-binding specificities of human integrins
Integrins	Ligands

α1β1	Laminin, collagen
α2β1	Laminin, collagen, thrombospondin, E-cadherin, tenascin
α3β1	Laminin, thrombospondin, uPAR
α4β1	Thrombospondin, MAdCAM-1, VCAM-1, fibronectin, osteopontin, ADAM, ICAM-4
α5β1	Fibronectin, osteopontin, fibrillin, thrombospondin, ADAM, COMP, L1
α6β1	Laminin, thrombospondin, ADAM, Cyr61
α7β1	Laminin
α8β1	Tenascin, fibronectin, osteopontin, vitronectin, LAP-TGF-β, nephronectin
α9β1	Tenascin, VCAM-1, osteopontin, uPAR, plasmin, angiostatin, ADAM [25], VEGF-C, VEGF-D [26]
α10β1	Laminin, collagen
α11β1	Collagen
αVβ1	LAP-TGF-β, fibronectin, osteopontin, L1
αLβ2	ICAM, ICAM-4
αMβ2	ICAM, iC3b, factor X, fibrinogen, ICAM-4, heparin
αXβ2	ICAM, iC3b, fibrinogen, ICAM-4, heparin, collagen [27]
αDβ2	ICAM, VCAM-1, fibrinogen, fibronectin, vitronectin, Cyr61, plasminogen
αIIbβ3	Fibrinogen, thrombospondin,, fibronectin, vitronectin, vWF, Cyr61, ICAM-4, L1, CD40 ligand [28]
αVβ3	Fibrinogen, vitronectin, vWF, thrombospondin, fibrillin, tenascin, PECAM-1, fibronectin, osteopontin, BSP, MFG-E8, ADAM-15, COMP, Cyr61, ICAM-4, MMP, FGF-2 [29], uPA [30], uPAR [31], L1, angiostatin [32], plasmin [33], cardiotoxin [34], LAP-TGF-β, Del-1
α6β4	Laminin
αVβ5	Osteopontin, BSP, vitronectin, CCN3 [35], LAP-TGF-β
αVβ6	LAP-TGF-β, fibronectin, osteopontin, ADAM
α4β7	MAdCAM-1, VCAM-1, fibronectin, osteopontin
αEβ7	E-cadherin
αVβ8	LAP-TGF-β

References are included for recently discovered ligands only. Abbreviations: ADAM, a disintegrin and metalloprotease; BSP, bone sialic protein; CCN3, an extracellular matrix protein; COMP, cartilage oligomeric matrix protein; Cyr61, cysteine-rich protein 61; L1, CD171; LAP-TGF-β, TGF-β latency-associated peptide; iC3b, inactivated complement component 3; PECAM-1, platelet and endothelial cell adhesion molecule 1; uPA, urokinase; uPAR, urokinase receptor; VEGF, vascular endothelial growth factor; vWF, von Willebrand Factor.
Takada et al. Genome Biology 2007 8:215 doi:10.1186/gb-2007-8-5-215