Has a role in the formation and organization of the extracellular matrix. In the eye, it functions as a mediator of dexamethasone-induced matrix deposition in the trabecular meshwork, the tissue responsible for the outflow of the ocular aqueous humor and for the maintenance of intraocular pressure (PubMed:21199193). Is a negative regulator of angiogenesis in the cornea, and plays a major role in maintaining corneal avascularity and transparency (PubMed:25622036). Homotetramer; disulfide-linked. Higly expressed in the cornea (at protein level) (PubMed:11682471). Expression is restricted to the stromal layer (PubMed:11682471). Also detected at the junction between the corneal stromal layer and the conjuctiva. Not detected in the sclera (PubMed:11682471). Expression is up-regulated by dexamethasone.