AD and PD may share several common pathways, such as abnormally folded protein clearance, neuroinflammation, endosomal dysfunction, neuroinflammatory process, lysosomal functions, etc. It was suggested that PSEN1 interacts with PD-related genes, including PRKN (or PARK2) and PINK1. The gene discussed is PSEN1; the disease is Alzheimer disease.