Table 2.

The expression of putative biomarkers in cornea and limbus.

Group of Putative Biomarkers	Putative Biomarkers	Corneal		Limbal		References
		Basal	Suprabasal	Basal	Suprabasal
Cell structural proteins	Vimentin	−	−	++	+	[59]
	CK5/14	−	−	+	+	[61]
	CK19	+++	+++	+++	+	[62]
	CK15	+	−	++	−	[63]
Cell adhesion molecules	Integrinα2	+++	+++	+++	+++	[64]
	Integrinα3	+++	+	+++	±	[64]
	Integrinα4	−	−	+	±	[64]
	Integrinα6	++	+	−	+++	[64]
	Integrinα8	−	−	±	±	[64]
	Integrinα9	−	−	+++	±	[65]
	Integrinβ1	+++	++	+++	+	[27]
	Integrinβ4	++	+	−	+	[59]
	P−cadherin	±	−	±	−	[59]
	E−cadherin	+	+++	−	+++	[36]
	N−cadherin	−	−	+	±	[36]
	Frizzled7	+	−	+++	++	[66]
Enzymes	α−enolase	++	+	+++	+	[65]
	cytochrome oxidase	++	+	+++	+	[67]
	Na+/K+−ATPase	++	+	+++	+	[67]
Growth factors and its receptors	EGF−R	+++	+++	+++	+	[27]
	KGF−R bek	±	−	−	−	[59]
	NGF−R TrkA	±	−	+	−	[51]
	NGF−R p75	++	−	++	−	[51]
	NGF	+	±	++	−	[51]
Cell cycle regulators	ΔNp63α	−	−	+++	±	[68]
ATP−binding cassette transporters	ABCG2	−	−	+++	±	[69]
	ABCB5	−	−	+++	++	[8]
Differentiation associated proteins	Cx43	+	+++	−	+++	[69]
	CK3/12	+++	+++	−	+++	[59]
	Involucrin	+	+++	−	+++	[70]

Note: −, no expression; ±, very weak expression; +, weak expression; ++, moderate expression; +++, strong expression.