APOE and Alzheimer disease: With the genes of these proteins and phosphopeptides related proteins, we created the Protein–Protein Interaction (PPI) network map of all differentially expressed mitochondria‐related proteins and phosphopeptides caused by APOE4 compared to APOE3 in AD mice in order to uncover the molecular basis of APOE4‐induced mitochondrial impairment at the presymptomatic stage of AD (Figure 6L).