This study utilized the APP/PS1-ob/ob animal model with both AD and T2DM and clearly demonstrated that the diabetic condition can aggravate cognitive impairment, Aβ deposition, tau phosphorylation, synaptic loss, neuronal death and inflammation in AD mice, and damage to calcium homeostasis may promote the progress of these pathophysiological processes. The gene discussed is PSEN1; the disease is type 2 diabetes mellitus.