SIRT1 and Alzheimer disease: In clinical research, an inverse relationship was observed between serum levels of SIRT1, SIRT3, and SIRT6 and AD.759 Measurement of SIRT1, SIRT3, and SIRT6 levels in saliva could be used as an additional method for intravital noninvasive diagnosis of AD in advanced age patients.760 The SIRT protein family constitutes a unique molecular link between aging and human neurodegenerative diseases and offers a promising avenue for therapeutic intervention.