OPTN and amyotrophic lateral sclerosis: The ALS-associated TBK1 E696K mutation specifically abolishes its binding to OPTN and disrupts OPTN/TBK1 complex formation (23, 34), this in contrast to the glaucoma-associated OPTN E50K mutation, shown to cause death of retinal ganglion cells in vitro and in transgenic mice (35), which enhances the interaction between OPTN and TBK1, affecting the oligomeric state of OPTN (34).