This suggestion is corroborated by two previous reports which demonstrated in an excitotoxic/ischemic model of glaucoma that increased OPN expression is restricted to the inner retina, particularly the IPL and the GCL (Chidlow et al., 2008), while in an autoimmune uveitis model OPN expression was dominant in the outer retina, particularly the OPL (Hikita et al., 2006). The gene discussed is SPP1; the disease is glaucoma.