The R15A inhibitor Sephin1 is a proteostatic enhancer found to be efficacious in two models of neurodegenerative diseases in mice associated with ER stress: Charcot-Marie-Tooth 1B (CMT-1B) and SOD1-ALS (Das et al., 2015, Tsaytler et al., 2011). Here, MPZ is linked to amyotrophic lateral sclerosis.