For instance, ACE2 converts Aβ43, an early-depositing species of Aβ that has been postulated to be an important seed for parenchymal plaque growth and is elevated in AD [88], to a less toxic Aβ species via sequential cleavage of Aβ43 to Aβ42 followed by ACE1-mediated cleavage to the less toxic Aβ40 [89]. Here, ACE is linked to Alzheimer disease.