MAPT and type 2 diabetes mellitus: Puzzlingly, while impaired glucose homeostasis has been suggested to increase AD risk and associated lesions and particularly tau pathology, AD patients have been reported to exhibit altered glucose metabolism (Bucht et al., 1983; Fujisawa et al., 1991; Craft et al., 1992; Matsuzaki et al., 2010; Calsolaro and Edison, 2016; Tortelli et al., 2017) and to display an increased prevalence to develop type 2 diabetes (Janson et al., 2004; for review see Gratuze et al., 2018).