In 2001, Huang et al. [43] reported that apoE4 could be cleaved into apoE4 (Δ272–299), which could promote the formation of neurofibrillary tangle-like intracellular inclusion body in neurons of AD patients and N2a cells following inducing apoE4 (Δ272–299) expression [43]. Here, APOE is linked to Alzheimer disease.