ATG5 and Alzheimer disease: In addition, researches show that autophagy is more efficient in young neurons than in old ones (Boland et al., 2008), as autophagy-related proteins such as Atg5, Atg7, and beclin-1 will decline with aging (Shibata et al., 2006; Lipinski et al., 2010), which probably contributes to the late onset of several neurodegenerative diseases including AD (Harris and Rubinsztein, 2011).