Amyloid precursor protein (APP) acts an essential role in neuronal development, including neuronal protein trafficking, neurite outgrowth, synaptogenesis, transmembrane signal transduction, intercellular adhesion, etc. The sequential cleavage product of APP after cleavage proteolysis by secretase and caspase is neurotoxic small peptide amyloid β (Aβ). Learn more: amyloid precursor protein secretase