Among these, APOE4 is considered the most potent risk factor for sporadic AD, accounting for 87% of AD cases.[8]APOE4 carriers show synaptic dysfunction and neuronal degradation accompanied by increased Aβ and tau aggregation.[9] Individuals carrying one APOE4 allele have double the risk of AD, while those carrying two APOE4 alleles have triple the risk, compared with individuals carrying two APOE3 alleles.[10] Therefore, uncovering APOE‐dependent disease phenotypes is highly needed to understand the pathophysiology of AD deeply. Here, MAPT is linked to Alzheimer disease.