MAPT and Alzheimer disease: Lipid and in particular ceramide metabolism alterations have also been reported in AD (Han et al., 2002; Wang et al., 2008; Mielke et al., 2010, 2012; Czubowicz et al., 2019), supporting a role for ceramide in promoting aggregation of Aβ associated with lipid rafts and spread of tau and amyloid beta (Aβ) via exosomes, as well as alterations in lipid metabolism associated with disease risk and progression.