In the study of Lau et al. [57], which also studied the salivary levels of Aβ42, Τ-tau and P-tau with ELISA, a more specific biosensor, namely extended gate ion-sensitive field-effect transistor (EG-ISFET), was also used to study trehalose, a sugar molecule associated with the pathophysiology of AD. This evidence concerns the gene MAPT and Alzheimer disease.