The optic nerve head is a critical structure in the primary pathophysiology of glaucoma and thus altering the morphology of this structure could influence glaucomatous phenotypes.3, 7 Genetic manipulation of a known JUN target gene, Bim, has been shown to alter vascular and optic nerve head morphology in DBA/2J mice.47, 48 To determine whether Jun deficiency altered optic nerve head morphology, Jun-deficient, Jun heterozygous, and wild-type animals were evaluated prior to the development of IOP elevation (<5 months). The gene discussed is JUN; the disease is glaucoma.