OPTN and open-angle glaucoma: Optineurin (OPTN) was first identified as a binding partner of an adenoviral E3 14.7 kDa protein and named “FIP-2” (for E3-14.7K-interacting protein) but after renamed to “optineurin” (for optic neuropathy inducing) since mutations in the OPTN gene had been identified in patients with primary open-angle glaucoma (1, 2).