APAF1 and Alzheimer disease: Based on NCBI database, the screened differentially expressed genes Apaf1, Bace2, and Plcb4 were enriched in the “Alzheimer's disease-reference pathway.” That is, these genes not only play an important role in the development of AD, but also their genes expression products were involved in apoptosis, Aβ formation, and cell or organelle membrane damage.