Apelin-13 is a neuropeptide which is capable of protecting against neuronal apoptosis and excitotoxicity in vitro, and is associated with neuronal survival in vivo following cerebral ischemia or ischemia/reperfusion injury, amyotrophic lateral sclerosis (ALS), and seizure [34,35,36]. Here, APLN is linked to amyotrophic lateral sclerosis.