MAPT and Alzheimer disease: A number of hypotheses have emerged to illustrate the pathogenesis of AD, mainly the amyloid cascade hypothesis (Savelieff et al., 2013; Butterfield and Halliwell, 2019; Hampel et al., 2021), tau protein hypothesis (Arnsten et al., 2021), metal ion disorder hypothesis (Savelieff et al., 2013), oxidative stress hypothesis (Butterfield and Halliwell, 2019), and cholinergic hypothesis (Hampel et al., 2018), etc. However, clinical trials so far have failed to demonstrate the efficacy of various therapeutics targeting the above mechanisms (Breijyeh and Karaman, 2020).