SNAP25 and amyotrophic lateral sclerosis: UNC13A and UNC13C for example, were among a group of exocytosis-related genes significantly downregulated in patient populations with ALS; downregulation of other vesicle-fusion regulatory proteins in ALS, such as SNAP25, is linked to the elevated intraneuronal calcium concentration and the resulting glutamate excitotoxicity associated with the pathophysiology of ALS [35].