PPP1R15A and amyotrophic lateral sclerosis: Both Sephin1, a PPP1R15A inhibitor, and ISRIB, an eIF2B activator, modulate PERK signalling and have been reported to exert neuroprotective effects in mouse models of amyotrophic lateral sclerosis (ALS) and prion disease (Das et al., 2015; Halliday et al., 2015).