GAPT and Alzheimer disease: Previous studies indicated that GAPT extract can markedly improves learning and memory of AD rat models made from hippocampal injection of Aβ1-42 peptide or intravenous injection of Aβ1-40 peptide [44], and reduces the level of Aβ in APPV717I transgenic mice via inhibiting γ-secretase (presenilin-1) and promoting insulin degrading enzyme and neprilysin [43].