Sephin-1 is a selective inhibitor of a regulatory subunit of protein phosphatase 1 (PPP1R15A), which plays a role in the integrated stress response (ISR) pathway. By modulating this pathway, Sephin-1 helps prolong the protective phase of the ISR, allowing cells more time to recover from stress conditions. This property makes it a promising candidate for the treatment of neurodegenerative diseases, such as amyotrophic lateral sclerosis (ALS), Alzheimer’s disease, and prion diseases, where protein misfolding and cellular stress are key contributors to disease progression. In preclinical studies, Sephin-1 has demonstrated the ability to delay disease onset, reduce neuronal loss, and extend survival in animal models without significant toxicity. Its neuroprotective effects, combined with good central nervous system penetration and oral bioavailability, support its potential as a disease-modifying therapeutic in chronic neurodegenerative conditions.