OPTN is one of the very few genes that have a large effect on glaucoma (Rezaie et al., 2002; Meng et al., 2012), and the mutations in OPTN that promote glaucoma but not those that promote Amyotrophic Lateral Sclerosis (ALS) act in a gain-of-function manner to promote more or dysregulated mitophagy (Wong and Holzbaur, 2014a; Sirohi et al., 2015; Shim et al., 2016). Here, OPTN is linked to amyotrophic lateral sclerosis.